I suggest

b) or e); extra doubtless e).

As a result of

This can be a transcription of Frère Jacques sung in a spherical in the important thing of C, omitting the treble clef and tails to crotchets and minims. Although the truth that the Dormez-vous? line is an octave under the Frère Jacques line signifies singers with two completely different ranges. If that is the purpose the place the half line repeats, then the reply is e); if it’s the level the place the strains change then the reply is b). I have a tendency in direction of e) as I would count on a 3rd singer to be launched with b).

My finest clarification for this title is

That this can be a Excessive High quality, two individual IQ Puzzle however with the primary half dropped by an octave.