Which of the following statements regarding foreign policy is correct?

a) Domestic policy has no effect on foreign policy, and foreign policy has no effect on domestic policy because they operate in different spheres.
b) Although foreign policy includes diplomacy, military, and security policy, it does not include international human rights policy.
c) Whereas foreign policy involves diplomacy, military, and security policy, foreign policy does not include economic policy.
d) Foreign policy includes various forms of economic policies, such as trade policy and international energy policy.