D (natural)
The subdominant note is D in an A major scale
The subdominant in any major scale is the fourth note. So, in C major, the subdominant is the F.
The subdominant is the 4th note in a scale, so in A major it's D.
The subdominant is the 4th scale degree. In G major, that's C.
The subdominant is usually the fourth scale degree of a major or minor scale.
The D note
A
G
A
The subdominant is the 4th scale degree. In the key of C major, the subdominant is F.
F Major
In a major scale the subdominant chord is a major chord,thus the dominant chord is major7.