The users request that [F2], [F3], and [F4] be used to commit, rollback, and exit,respectively. How do you accomplish this?（）

A、Add the appropriate PL/SQL code for each key. 

B、Map the logical keys to the physical keys, then add the appropriate PL/SQL code for each key.

C、Create an object library to define the key triggers, then reference the object library in the form. 

D、This cannot be accomplished because other function keys provide this functionality by default.