As You Are Walking Out of Class One Night,you Discover

As you are walking out of class one night,you discover a notebook,full of equations,belonging to a professor in your school.You write a note telling him who you are and where and when you found it,and you drop the note in an envelope,into one of the university's internal mail boxes.The next day the campus is covered with notices which say "$100 REWARD.A notebook containing mathematical explanation of the meaning of life has been lost.If found,please return to Professor Doddering in Room A123."

A) You have no legal right to the $100.
B) You have a legal right to the $100 since you can prove you put the note in the mail to Prof.Doddering.
C) You have a legal right to the $100 provided you can prove you found it after Prof.Doddering posted the reward notices.
D) Since this was an offer to the public at large,you have accepted it by mailing it and Prof.Doddering legally must give you $100.
E) While you have no legal right to the reward,the court will enforce your moral right to it.