Which of the following is the most reliable indicator of the existence and intensity of acute pain? 1. The client's vital signs. 2. The client's self-report of pain. 3. The nurse's assessment of the...

Which of the following is the most reliable indicator of the existence and intensity of acute pain?

1. The client's vital signs.

2. The client's self-report of pain.

3. The nurse's assessment of the client.

4. The severity of the condition causing the pain.