Which of the following is unlikely to indicate that a person is in pain?

Indicating that a person is in pain typically involves visible expressions or complaints related to discomfort. When a person volunteers to clean up their own room, it suggests that they are capable of engaging in activities and may not be experiencing pain at that moment. This behavior generally implies motivation and willingness rather than signs of distress.

In contrast, limping when walking, becoming angry without an apparent reason, or complaining about hurting clearly indicate discomfort or pain. Limping can be a physical manifestation of pain, while behavioral changes like anger can stem from frustration or irritability commonly associated with pain. Complaints of hurting are the most direct expression of experiencing pain. Thus, the act of volunteering to do a task that requires physical effort is unlikely to correlate with being in pain, making it the correct choice in this context.