Choose the Answer Which Best Rewords the Italicized Portion

Choose the answer which best rewords the italicized portion. If you think the original wording is best, choose option A.
The crisis between the United States and North Vietnam intensified when North Vietnam attacked the U.S.S. Maddox off the coast of North Vietnam.

A) The crisis between the United States and North Vietnam intensified when North Vietnam attacked the U.S.S. Maddox off the coast of North Vietnam.
B) The crisis between the United States, and North Vietnam intensified when it attacked the U.S.S. Maddox off the coast of North Vietnam.
C) The crisis intensified when North Vietnam attacked the U.S.S. Maddox off its coast.
D) The crisis grew after the United States and North Vietnam attacked the U.S.S. Maddox off the coast of North Vietnam.