Two Boys Held Up a Liquor Store at Gunpoint and Ran

Two boys held up a liquor store at gunpoint and ran off with a bag of money. The police saw them run into Jill's apartment building where there are only four apartments off a common hall and no apparent way out of the building but the front door. The police knock on Jill's door. She says she's the only one there. The police can:

A) search the apartment without a warrant because Jill voluntarily answered the door.
B) search the apartment without a warrant because they are in hot pursuit of the thieves.
C) not search the apartment, because they have no reason to believe that the boys are in Jill's apartment rather than the others.
D) not search the apartment because voluntary consent to enter is necessary.