Final answer:
The leader of an army inspires the ship crew to halt the flight to the ships.
Step-by-step explanation:
The answer to the given question is D. Leader inspires ship crew. According to the information provided, the leader of an army has the ability to inspire and motivate the ship crew to halt the flight to the ships. This is supported by the statement, 'At the critical moment, the leader of an army acts like one who has climbed up a height and then kicks away the ladder behind him. He carries his men deep into hostile territory before he shows his hand.'