Adding an A on the second space, directly above the F, would make this chord a

A. root-position triad.

B. first-inversion triad.

C. second-inversion triad.

D. third-inversion triad.

Adding an A on the second space, directly above the F, would make this chord a C. second-inversion triad. The first inversion of a chord is the voicing of a triad, seventh chord, or ninth chord with the third of the chord in the bass and the root a sixth above it.