On November 1, the following notice was posted in a privately operated law school: The faculty, seeking to encourage legal research, offers to any student at this school who wins the current National Obscenity Law Competition the additional prize of $500. All competing papers must be submitted to the Dean's office before May 1. (The National Competition was conducted by an outside agency unconnected with any law school.) Student read this notice on November 2, and thereupon intensified his effort to make his paper on obscenity law, which he had started in October, a winner. Student also left on a counter in the Dean's office a signed note saying, "I accept the faculty's $500 Obscenity Competition offer." This note was inadvertently placed in Student's file and never reached the Dean or any faculty member personally. On the following April 1, the above notice was removed and the following substituted therefor: The faculty regrets that our offer regarding the National Obscenity Law Competition must be withdrawn. Student's paper was submitted through the Dean's office on April 15. On May 1, it was announced that Student had won the National Obscenity Law Competition and the prize of $1,000. The law faculty refused to pay anything."The offer proposed a
unilateral contract only. bilateral contract only. unilateral contract or bilateral contract at the offeree's option. unilateral contract which ripened into a bilateral contract, binding on both parties, as soon as Student intensified his effort in response to the offe