Final answer:
To communicate nonverbally that you understand a speaker's idea, smile and nod slightly while maintaining eye contact. Avoid negative gestures like slumping or fidgeting, as they suggest disinterest. Sitting upright and remaining still will also convey attentiveness. The correct answer is option O Smile and nod slightly.
Step-by-step explanation:
To silently let a speaker know that you understand the idea, you can utilize positive body language. Smiling and nodding slightly is a common nonverbal gesture that indicates to the speaker that you are following along and comprehend what is being said. This gesture, coupled with maintaining eye contact, displays engagement and interest in the conversation.
Conversely, slumping, fidgeting, or looking away can be perceived as a lack of interest or understanding. Therefore, adopting a posture that conveys attentiveness – such as sitting upright and remaining still – can further communicate that you are a good listener and are actively processing the speaker's words.