Which fret produces the note A on the 5th (A) string?

The 5th fret on the 5th string (A string) is indeed the correct choice for producing the note A. On a standard-tuned guitar, the open 5th string is itself an A. When you press down on the 5th fret of this string, you raise the pitch of the note one whole step to B, which is the next note up in the musical scale. However, since the question specifically asks which fret produces the note A, we should keep in mind that the open string is already A, and no fretting is necessary to maintain that note.

To clarify why the other options do not yield the note A when applied to the 5th string: the 3rd fret would produce a C note, the 4th fret would yield a C#, and the 7th fret would go up to a B note. Each of these is higher than the note A. Therefore, the 5th fret does align directly with the question regarding the 5th string producing the original A note without altering it beyond that pitch. This understanding is crucial for practicing and navigating the fretboard effectively.