Concept:The blank must be filled with a phrasal verb that means to make the lights stop shining.
Explanation:In this sentence, the subject is "We," and the verb must describe an action done to the lights.
The correct phrasal verb is "put out," which means to extinguish or turn off something like a light or fire.
For example, we can say: "We always put out the lights before going to bed."
Option B, "put off," means to postpone a plan or event, which is completely different in meaning.
Option A, "off," and option D, "out," are not verbs, so neither can act as the main verb in the sentence.
Therefore, the only answer that is both grammatically correct and meaningful is C, "put out."
Answer:C. put out