Jackson, a young naval officer, is on board a crew ship sailing in the North Atlantic Ocean. He detects a ship intruding their territory and informs the captain. The captain asks him to ignore it as the intruder is 10 nautical miles away from them. He obeys the order and discounts his misgivings even though he believes that they should take immediate action against the intruder. In the context of Janis's groupthink symptoms, which of the following does this scenario exhibit? A. the presence of a mindguard B. self-censorship C. rationalization D. the illusion of unanimity