A Fire Threatens to Engulf a Commercial Building in Metro

Multiple Choice

A fire threatens to engulf a commercial building in Metro City. The building's owner promises a cash reward to the Metro Fire Department to extinguish the fire. The firefighters cannot claim the reward because

A) extinguishing the fire is the firefighters' preexisting duty.
B) extinguishing the fire represents past consideration.
C) extinguishing the fire is a foreseen difficulty.
D) the promise of a cash reward is illusory.