WASHINGTON — Which offense is likely to carry a bigger fine soon in Washington, D.C.?

a) Parking near a fire hydrant.

b) Possessing pot.

If you answered “a,” you are correct: Possession of less than an ounce of marijuana would be a civil infraction with a $25 fine under a plan that won easy approval Tuesday from the District of Columbia City Council.

Backers called it one of the most lenient decriminalization laws in the nation and said the next step would be to make marijuana fully legal in the nation’s capital, as Colorado and Washington state did in 2012.

The bill passed on a 10-1 vote. Once it’s signed by Mayor Vincent Gray, Congress will have 30 working days to review the new law, which means it might not take effect until summer. Congress has the authority to overturn any laws the council passes.

Congress put D.C.’s medical marijuana plan on ice after it passed in 1998, but no one’s expecting a peep of opposition on Capitol Hill this time, another sign of the drug’s surging public acceptance, as reflected by public opinion polls.

“This is just not on their radar,” said Dan Riffle, the director of federal policies for the Marijuana Policy Project. “The story is just how much things have changed. Congress just doesn’t care because they’ve got the message this is really popular.”

D.C. council members who backed the change argued that the current penalty – a fine of up to $1,000 and a possible six-month prison sentence for possessing any amount – hit minorities disproportionately hard. Studies show the District of Columbia has a higher marijuana arrest rate than any state, with blacks accounting for 90 percent of the cases.

“One drug charge can change a life forever,” said council member Tommy Wells, the bill’s chief sponsor, who called Tuesday’s decision a “historic vote.”

Critics said the measure didn’t go far enough, by still allowing police to issue citations but not permitting D.C. to collect tax revenue from legal marijuana sales.

“Decriminalization is missing out on the tax base, and it’s treating the user still like a second-class citizen,” said Adam Eidinger, chairman of the D.C. Cannabis Campaign. He was upset that the council decided to amend the legislation to add a $500 fine and a possible 60-day jail sentence for smoking marijuana in public, thus keeping it a criminal offense.

“If you can smoke a cigarette on the sidewalk, you should be able to smoke a joint on a sidewalk. There really is no difference,” Eidinger said.

Things could get a little confusing, with marijuana possession on federal property remaining a federal crime, punishable by a fine of $1,000 and jail time. The federal government owns nearly 22 percent of the land in the federal capital.

“A map of D.C. will be needed, as there will a hodgepodge of laws and enforcement based on where one is standing at any given moment,” said Allen St. Pierre, executive director of the National Organization for the Reform of Marijuana Laws.

Riffle said most people who violated the law on federal property were fined from $100 to $200. He expects the disparity to continue.

“It’s just part of the cluster that is D.C. law,” Riffle said. “I can tell you, as a D.C. resident myself, there’s a lot of things that don’t make sense about the way D.C. is treated.”

Council member Yvette Alexander, who cast the only dissenting vote, said it made no sense to have a law that decriminalized possession of marijuana while its sale and consumption in public remained criminal offenses.

“There will still be arrests when someone is smoking marijuana on the corner,” she said, urging the council to take a comprehensive look at the issue. “You can’t deal with little sections of this bill.”

Eidinger said he backed decriminalization only as a way of “breaking the ice” while legalization backers in D.C. remain focused on getting the issue on the November ballot.