Please check my answers, if I have a wrong answer please tell me what the correct answer is

1. The ____ triad is built on the second scale degree.
   

Amediant

Bsubmediant (my answer)

Csupertonic

Dleading-tone

1. In a major key, the minor diatonic triads are
   

Amediant, dominant, and submediant (my answer)

Bsubdominant, dominant, and tonic

Csupertonic, subdominant, and dominant

Dsupertonic, mediant, and submediant

1. In the key of C, the D-major chord is the
   

Atonic (my answer)

Bsubdominant

Cmediant

Dsupertonic

1. The _____ is the most stable-sounding diatonic triad.
   

Atonic

Bsubdominant (my answer)

Cmediant

Dsupertonic

1. The _____ sounds unstable because it is diminished.
   

Asupertonic (my answer)

Bsubdominant

Cleading tone

Dsubmediant