Final answer:
An A-sharp is a major third (M3) above an F-sharp, which is determined by counting four semitones from the starting note.
Step-by-step explanation:
The pitch that is a major third (M3) above an F-sharp is an A-sharp. In Western music theory, a major third above any note is four semitones higher. Starting from F-sharp, which is one semitone higher than F, we count up four semitones: F-sharp to G (1), G to G-sharp (2), G-sharp to A (3), and A to A-sharp (4). Therefore, the note A-sharp is a major third above F-sharp.