Read the passage carefully and answer the question that follows. One day an army group won a lond battle against the enemy. The commander feared that the enemy's powerful air force might bomb his camp that night in revenge. So he ordered all lights to be put out at 7:00 PM. At midnight the comman went round inspecting the camp. Seeing a light in a tent, he entered it. His son, an officer under him, was writing a letter. The son explained that he was writing to his mother about his brave deeds in battle. The commander told his son to add to his letter that by the time his mother received the letter he would have been shot dead for indiscipline.
The commander went round the camp at midpoint because he

Options

A. was too tired from the day's battle to go to sleep
B. wished to check if his soldiers had obeyed his order
C. was too worried about the next day's battle
D. wished to check if enemies had entered his camp