Question

complete the sentence.
________ reflexes and automatic functions such as heart rate and digestion, but it also controls the movement of eyes, arms, and legs.
the brain stem controls not only
not only does the brain stem control

Explanation:

The sentence uses the correlative structure "not only...but also...". When "not only" starts a clause, subject-verb inversion is required. The second option correctly inverts "the brain stem" and "does/control" to match the grammatical rule for this structure, while the first option would create a run-on or grammatically incorrect sentence if placed in the blank.

Answer:

Not only does the brain stem control