The correct answer is B) He ordered US military assistance for South Korea.
President Truman responded to the hostilities on the Korean Peninsula in the following way: He ordered US military assistance for South Korea.
After the incidents of the Korean Peninsula, on June 27, 1950, US President Harry S. Truman ordered military assistance to South Korea. On June 25, 1950, the North Korean army had invaded South Korea and that is why President Truman sent the Navy and the Air Force to the Korean peninsula. These incidents were part of the Cold World years in which the Soviet Union wanted to spread Communism in many countries and the United States tried to stop it.