Final answer:
The correct answer is option 2) go. Peter and his friends go to school by bus.
Step-by-step explanation:
The correct answer is option 2) go. Peter and his friends go to school by bus.
We use the present simple tense for regular activities or habits. In this case, going to school by bus is a regular activity for Peter and his friends. Since the subject is plural (Peter and his friends), we need to use the plural form of the verb, which is 'go'.
Learn more about Present Simple Verb Tenses