During the 179os, one way Congress applied the
elastic clause was by
(1) establishing a national bank
(2) creating a national postal system
(3) adding Vermont and Kentucky as states
(4) approving the Jay Treaty with Great Britain



Answer :

During the 1790s, one way Congress applied the elastic clause was by "(1) establishing a national bank". This was not an explicit idea of the power given to Congress. 
The correct answer is (1) establishing a national bank

The elastic clause establishes that the government may pass or introduce new acts that are not within their enumerated powers, but that helps them be able to use these enumerated powers. The power to establish a national bank was not enumerated, but without it they wouldn't be able to have those enumerated powers so they established it.