Increased Activity in the Cells of the Ventral Respiratory Group

Increased activity in the cells of the ventral respiratory group of the medullary respiratory center is expected to produce

A) increases in the contraction of the external intercostals muscles.
B) increases in the contraction of the internal intercostals muscles.
C) increased contraction of the abdominal muscles.
D) All of these changes.
E) no change in breathing whatever.