He was practicing deep breathing techniques, he had to have great control of his what?\nOptions:\n- bringing air into body bringing air into lungs\n- abdominal muscles\n- bringing air into lungs\n- air\n- oxygen
Think hard. Detailed solution:
abdominal muscles
Deep breathing uses the abdominal muscles.

Abdominal muscles are a group of muscles.

The intensity of using abdominal muscles requires control.

.

The answer is abdominal muscles