Final answer:
Nonverbal communication during oral communication exchanges has a significant impact on the message being conveyed. Nonverbal cues can reinforce the meaning of the verbal message and express up to 70% of the sender's intended meaning.
Step-by-step explanation:
Nonverbal communication during oral communication exchanges has a significant impact on the message being conveyed. Nonverbal cues, such as gestures and facial expressions, can reinforce the meaning of the verbal message. In fact, research suggests that nonverbal communication can express up to 70% of the sender's intended meaning. Therefore, option c. It can express up to 70% of the sender's meaning, is the best description of the effect of nonverbal communication during oral communication exchanges.