Facial expressions are mainly used to convey which of the following?

Facial expressions serve as a crucial means of nonverbal communication primarily associated with the transmission of emotions. Options that focus on broad concepts like internal conflicts or complex interpersonal communication might cover a range of human interactions, yet they do not directly pinpoint the specific content conveyed by facial expressions.

Emotions like fear and surprise are universally recognized and can be identified through distinct facial configurations, making them a central aspect of how we communicate feelings without words. This ability to express emotions visually helps individuals understand each other's emotional states quickly and often triggers responses that align with those emotions.

While aspects like nonverbal signals of agreement can certainly be expressed through facial gestures, they do not encapsulate the primary function of facial expressions as effectively as the recognition and conveyance of basic emotions. Thus, the focus on fear and surprise captures the essence of what facial expressions predominantly communicate in interpersonal contexts.