[Bank Robbery] Safe Bank Was Robbed of a Significant Sum

[Bank Robbery] Safe Bank was robbed of a significant sum of cash by a robber later identified as Victor Victory. Safe Bank offered a reward of $10,000 to anyone who captured or provided information leading to the capture of Victor. Kareem, a police officer in town, promised Safe Bank officials that he would apprehend Victor. While on duty, Kareem arrested Victor at a restaurant in town. He found Victor after Ursula, Victor's girlfriend, told Kareem about various places Victor enjoyed eating. The bank refuses to pay either Ursula or Kareem any of the reward money.
-In a lawsuit between the bank and Kareem regarding the reward funds, who is likely to prevail and why?

A) The bank is likely to prevail because Kareem only provided past consideration.
B) The bank is likely to prevail because Kareem had a preexisting duty to catch Victor.
C) The bank is likely to prevail because Kareem's promise to catch Victor was illusory.
D) Kareem is likely to prevail because his promise to catch Victor resulted in a binding bilateral contract.
E) Kareem is likely to prevail because an enforceable unilateral contract exists based on his performance.