The "Syndicate" refers to a group of senior Congress Party leaders who were opposed to Indira Gandhi’s leadership. They were not opposition leaders from outside the Congress Party, but rather powerful figures within the party who resisted her centralization of power. The Grand Alliance, on the other hand, was formed by opposition parties outside the Congress to challenge Indira Gandhi.
Thus, the incorrect pair is (C), as the Syndicate was not made up of opposition leaders but Congress leaders.
Thus, the correct answer is (C) Syndicate – A group of powerful opposition leaders against Indira Gandhi.