hi would it be possible to help me with these questions, not sure i understand how to go about solving this and am lost.

Question #2 #2: Identify the sampling technique used. Discuss the potential for bias (if any). Justify your reasoning. a) Questioning students as the left the library, a researcher asked 285 students about their study habits. b) Chosen at random, 928 customers who had purchased a car at the We Sell Cars car lot were contacted and asked to give their opinion on their car buying experience. c) A researcher selects one classroom at random and then surveys all of the students in the classroom