Question

Which respiratory-associated muscles would contract or relax during forced expiration, for example blowing up a balloon?

Answer 1

The correct answer is B, internal intercostal muscles and abdominal muscles would contract.
Exhalation is the flow of the breath out of the body. During forced exhalation, internal intercostal muscles contracts which lower the rib cage and decrease thoracic volume, while the abdominal muscles push up on the diaphragm which causes the thoracic cavity to contract. 

Answer 2

Internal intercostals and abdominal muscles would contract.

Exhalation is the flow of the breath out of an organism. In humans it is the movement of air from the lungs out of the airways, to the external environment during breathing.