Which harmony is the most appropriate for the notes in the rectangle?

ANSWER

The sequence makes repeated dominant and tonic chords in different keys. The first chord in the measure is a pivot chord between c minor and bb minor, there comes another dominant chord in a new key. The marked chord is a minor 7th chord consisting of C, Eb, G and Bb. Correct answer is 1.
Which harmony is the most appropriate for the notes in the rectangle?
ANSWER
The sequence makes repeated dominant and tonic chords in different keys. The first chord in the measure is a pivot chord between c minor and bb minor, there comes another dominant chord in a new key. The marked chord is a minor 7th chord consisting of C, Eb, G and Bb. Correct answer is 1.