Question

which quote from the story best supports the idea that brennan watches mr. nelson’s conducting in an effort to hold back his tics, or involuntary noises and movements?
actually, he was practically consumed by the motions.
the chorus was singing \defiance,\ brennan’s favorite.
sometimes, the perfect regularity of mr. nelson’s conducting was enough to stop him from doing anything.
but the impulse barreled over the gate he tried to put up in his mind.

Explanation:

This quote directly states that Brennan's focus on Mr. Nelson's conducting fully occupied him, which would naturally hold back his involuntary tics by diverting his attention and mental energy. The other quotes do not link Mr. Nelson's conducting to managing Brennan's tics.

Answer:

Actually, he was practically consumed by the motions.