FACTS: On December 5, Sebastian, a graduate student, offered to sell Burnie his autographed Miami Hurricanes football jersey for $400. Burnie replied that he thought $400 might be more than he wanted to pay for the jersey. Burnie asked Sebastian to hold the offer open for 5 days while he considered the offer. Sebastian agreed. On Dec. 6, Sebastian sold the jersey to Shaq for $450. On Dec. 7, Burnie told Sebastian he accepted his offer to buy the jersey for $400.
A. Did Sebastian have an enforceable contract with Burnie so that Sebastian was obligated to hold the offer open for 5 days while Burnie considered Sebastian's $400 offer? Why or why not?