Which of the following is NOT one of the roles of the president?
a. commander-in-chief
b. chief diplomat
c. chief interpreter of the constitution
d. chief justice
The president cannot be chief justice - this would be a breach of the separation of powers. Chief Justice is a member of the judicial branch of the government; and the president is the head of the executive branch of the government, so they should not be the same person - the answer is d)