In 2013, United States Secretary of State John Kerry signed a United Nations arms treaty.That treaty was submitted to the United States Senate, and fifty-one senators approved it. That treaty:

a. is binding law in the United States because it was signed by a high-ranking U.S. official.

b. is binding law in the United States because a majority of the Senate ratified it.

c. is not binding law in the United States because treaties are not binding.

d. is not binding law in the United States because it was not ratified by two-thirds of the Senate.