Java:

A teacher included three extra credit questions on a test and awarded 3 extra points to students who answered all three questions correctly and no extra points otherwise. The boolean variables extraOne, extraTwo, and extraThree indicate whether a student has answered the respective question correctly. Each variable would be assigned a value of true if the answer was correct and false if the answer was incorrect.

Which of the following code segments will correctly update the variable grade based upon a students answers to the extra credit questions?

I. if ( extraOne && extraTwo && extraThree ) grade += 3;

II. if ( extraOne || extraTwo || extraThree ) grade += 3;

III. if ( extraOne ) grade += 3;

if ( extraTwo ) grade += 3;

if ( extraThree ) grade += 3;