Final answer:
The buccinator muscle, option a, is responsible for compressing the cheeks, which allows for actions like sucking and blowing air.
Step-by-step explanation:
The muscle that compresses the cheeks to allow sucking and blowing air is the buccinator muscle. This muscle is significant as it facilitates important actions such as whistling, blowing, and sucking, as well as contributing to the chewing process.
Unlike the occipitofrontalis, which consists of the frontal and occipital bellies for moving the scalp and eyebrows, and the orbicularis oris, which is responsible for lip movements, the buccinator is the primary muscle that enables lateral movement of the cheeks, essential for actions such as sucking on a straw or compressing air in the mouth while blowing.