Correct Answer: officiates

Solution : The third option is the correct answer.

Officiates means to perform the duties of an office, especially to act as an official in charge during the temporary absence of the regular occupant. This aligns with the context.

The meanings of other options are as follows:

• Depute means to appoint or assign someone as a deputy or substitute.
• Exchanges mean to trade or replace something with something else.
• Replace means to take the place of someone or something.

Therefore, the complete sentence is, "In the absence of the principal, the vice principal officiates for him."