A local gymnasium is trying to find out what additional classes they should offer. They send out 50 surveys to a random selection from all of their customers and follow up with phone calls to those that they don't get a response from. Is this a good way for the gym to collect data?

A) No, they should send out surveys to all of their customers.
B) Yes, by randomly selecting them they will get a representative sample.
C) No, they should just survey the next 50 customers that come to the gym.
D) Yes, but they shouldn't follow up with phone calls. Just look at the ones that were returned.