The correct answer is A) when he tried to establish a confederation of states with authority over the national government.
John C. Calhoun coined the phrase “states’ rights” when he tried to establish a confederation of states with authority over the national government.
John C. Calhoun (1782-1850) was a Democrat Senator form South Carolina and vice president of the United States that supported slavery and thought it was positive for the states. He had many differences with President Andrew Jackson, mainly for the Nullification crises in the state of South Carolina, and the Petticoat affair.
The other options of the question were B) in arguments about federal interference with southern states practicing slavery. C) in a speech in which he argued against the establishment of a National Bank. D) when he fought for the "separate but equal" clause established in Plessy v. Ferguson.