Correct Answer: Let us preserve these ancient texts for posterity.

Solution : The first option is the correct answer.

In the original passive sentence, the doer of the action is not explicitly mentioned. In active voice, we introduce a clear doer of the action, which is us. The original passive construction uses the verb be preserved.

Preserve is a suitable choice to convey the idea that they will actively undertake the preservation. In active voice, the sentence starts with the subject (us), followed by the verb (preserve), and the rest of the information.

The structure of active voice sentences is, " Imperative verb + subject + base form of verb + direct object + prepositional phrase."

Therefore, the correct answer is, " Let us preserve these ancient texts for posterity".