Select the option that expresses the given sentence in active voice.

The problem will be solved by my friend.

My friend will solve the problem.

The correct option that expresses the given sentence in active voice is My friend will solve the problem.

The other options are incorrect because:

• The problem will be solved by my friend is in the passive voice.
• My friend was solved the problem is grammatically incorrect. The verb "to solve" is transitive, which means that it takes a direct object. However, the subject of the sentence is "my friend," which is not a direct object.
• My friend will be solving the problem is in the future progressive tense, while the original sentence is in the future tense.
• My friend solves the problem is in the present tense, but it does not specify when the problem will be solved.