According to Ader and Cohen (1985) classical conditioning even works on the body's disease-fighting immune system. According to this research, which of these would be the MOST likely to produce this response?

repeated pairing of coffee with the immune enhancing drug

Explanation:

According to Ader and Cohen (1985) in their research on classical conditioning, it was concluded that classical conditioning works on the immune system of the body responsible for fighting diseases. They asserted in their research that repeated pairing of coffee with immune enhancing drugs would condition the body to activate the immune system.