Which amendment finally made it unconstitutional to deny suffrage based on sex?
a. fourteenth amendment
b. fifteenth amendment
c. nineteenth amendment
d. twenty-first amendment

The correct answer is: the Nineteenth Amendment.

Women gained voting rights in the US later than people of colour, as this Amendment was passed in 1920 and the Fifteenth Amendment, which prohibits racial discrimination when voting, was passed in 1870.

B) His religion.

Explanation:

Kennedy was a Roman Catholic, and, since no Catholic had ever won the  Presidential election before, his capacity to prioritize national interests over the Vatican´s agenda was doubted, as well as his electability in the Bible Belt South. Despite his statements about the importance of separating church and state, his religion may have cost him an around 1.5 million votes in that election. Nevertheless, he won the Presidency.