Correct Answer: The officer said to his boss, “My men are leaving tomorrow by plane.”

Solution : The correct choice is the fourth option.

The direct form of a sentence is a way of expressing the same message without using reported or indirect speech. In direct form, the information is conveyed straightforwardly, without any intermediary reporting verb like "informed" or "said".

The steps of conversion are as follows:

• Removing the reporting verb ("informed")
• Keeping the reporting clause intact ("his boss").
• Changing the pronouns ("his" to "my").
• Changing the verb tense from past to present ("were leaving" to "are leaving").
• Adding quotation marks around the reported speech ("My men are leaving tomorrow by plane").

Therefore, the direct form would be: The officer said to his boss, “My men are leaving tomorrow by plane.”