What is the note played on the G (3rd) string 2nd fret?

The note played on the G string at the 2nd fret is an A. To understand why this is the case, it's important to know how the guitar fretboard is laid out. The G string is the third string of the guitar and is tuned to G in standard tuning.

Each fret on the guitar represents a half step, or semitone, so when you press down on the 2nd fret of the G string, you raise the pitch of the open G note by two half steps. The first fret on the G string would play G#, and then when you move to the 2nd fret, you move up another half step to reach A. Therefore, the correct note at the 2nd fret of the G string is indeed A.

In this context, the other options are not applicable as they do not correspond to the note played at that particular fret location. The G string, when played open, is G. Moving to the first fret gives you G#, and the second fret gives you A, thus confirming A as the correct answer.