Which of the following techniques would be categorized as a control tactic?

The choice of joint locks as a control tactic is correct because joint locks are aimed at manipulating an individual's joints to control their movement and ensure compliance without causing serious harm. This technique is foundational in control tactics and self-defense training, allowing officers or individuals to effectively restrain a subject while minimizing the risk of injury to both the officer and the subject. Joint locks leverage biomechanics and the vulnerable nature of joints to achieve compliance, making them a non-lethal option that emphasizes control over aggression.

Other methods listed, such as firearm discharge or the use of chemical agents, are more geared toward incapacitating a threat rather than controlling a situation with minimal force. Similarly, surprise attacks are offensive strategies rather than control tactics focused on restraint and de-escalation. Therefore, joint locks stand out as a technique specifically designed for control within the context of law enforcement and self-defense situations.