Carlos wants to find out the favorite summer time activity for the students of his entire school. Which of the following methods could he use to produce a random sample?

Poll 5 random people out of each 7th grade homeroom
Poll every 10th student that comes into the cafeteria during the entire lunch period.
Poll every third student that comes into the boy's gym locker room.
Poll every sixth student that enters the media center.

Carlos could use the first method: poll 5 random people out of each 7th grade homeroom. This method ensures that he is getting a representative sample of the entire school population since it includes students from different grades and homerooms. The other three methods may introduce bias as they are only polling students from specific locations or groups within the school.