Final answer:
The client's nonverbal behaviors of maintaining eye contact and leaning forward during an interview suggest that they are engaged and attentive. These indicators are fundamental components of nonverbal communication that convey interest and alertness in the interaction.
Step-by-step explanation:
During a client's initial interview in a mental health inpatient setting, a nurse notices that the client is maintaining eye contact and leaning forward. These behaviors indicate that the client is engaged and attentive. In the context of nonverbal communication, direct eye contact typically signifies an individual's engagement and alertness in a conversation, which is essential in an interview setting. Additionally, leaning forward can imply interest and a willingness to be part of the dialogue. Contrarily, signs of agitation, hostility, disinterest, or hallucinations would generally involve different behaviors such as avoiding eye contact, appearing distracted, or showing aggressive body language. Therefore, based on the client's nonverbal behaviors, the assumption the nurse should make is that the client is engaged and attentive (C).