A) First, I would ask: What pets does your family have at home? B) I would choose the population of the entire school. To ensure a truly random sample, I would give everyone in my sample a number and then use a random number generator to pick my sample.
Work Step by Step
C) This part must be done on your own, for I am not able to accurately describe the pets that families at your school will own. I would imagine, however, that dogs and cats are near the top of the list.