Zachary Plays the Piano for a Half Hour and Gains

Multiple Choice

Zachary plays the piano for a half hour and gains utility of 7.He then watches TV for a half hour,then goes back to playing the piano again.Using the concept of utility to explain his choices,we can say:

A) the utility gained from watching TV was greater than playing the piano for a second half hour.
B) Zachary revealed his preference for TV over a second half hour of playing piano.
C) Zachary enjoys playing the piano for a half hour more than watching TV for a half hour.
D) All of these are true.