Answer:
Right choice:
b. grant reprieves, pardons, and amnesties.
Explanation:
A US president can´t sign secret agreements with other nations, because he doesn´t have the power to and the Senate has to ratify any foreign treaty. Neither can a president call special sessions of Congress. But he can grant pardons. Annually, he does that. Sometimes, some pardons are motivated politically as when president Gerald Ford pardoned former president Richard Nixon for the crimes he committed in the Watergate case.