The correct answer is C. A blockade was considered an act of war.
Step-by-step explanation
In the middle of 1962, American spy planes recognized on the island of Cuba some forms that seemed to be missiles that would easily overcome the distance that separated the island from the continental United States. Therefore, on October 1962, US President John F Kennedy announced that quarantine and a "naval siege" would be established in Cuba, for which ships and planes were sent to the Caribbean Sea. In response to the above, the Russian President of the time Nikita Khrushchev referred to the fact saying that he considered the encirclement as aggression, also, he ordered the Soviet ships to slow down to avoid any major conflict if they encountered US ships. According to the above, the correct answer is C. A blockade was considered an act of war.