Answer:
Correct, the answer is B: the statement "It was misunderstood by Johnson and caused the United States to become more involved in Vietnam" is true. The Gulf of Tonkin incident was a series of events that occurred in August 1964, involving U.S. and North Vietnamese naval forces in the Gulf of Tonkin. President Johnson used these events as a pretext to escalate U.S. involvement in the Vietnam War, but later evidence suggested that the second attack on the U.S. Navy never actually occurred.