Research Applying the Principles of Classical Conditioning to Boost or Suppress

Multiple Choice

Research applying the principles of classical conditioning to boost or suppress the immune system has found that:

A) only the immune systems of animals can be effectively manipulated by these techniques.
B) the functioning of the immune system can only be suppressed and not boosted.
C) these principles must be used in combination with operant conditioning to be effective.
D) the immune systems of both animals and humans can be boosted or suppressed.