What is the primary purpose of a chemical agent?

The primary purpose of a chemical agent is to kill, injure, or incapacitate military personnel or intended targets. Chemical agents are designed specifically to be harmful, and they can disrupt enemy operations by causing casualties or rendering individuals unable to fight effectively. This main characteristic sets chemical agents apart from other options, which serve purposes unrelated to combat effectiveness.

For instance, while first-aid training is important in a military context, it does not align with the offensive purposes of chemical agents. Enhancing food preservation and cleaning military equipment are logistical functions that don't involve the use of chemical agents for the intended harmful effects. Thus, the correct answer underscores the offensive capability of chemical agents in warfare, emphasizing their role in incapacitating adversaries.