Sampling and bias

Suggest a change in each sampling process to eliminate bias. In other words, what type of sampling would be more appropriate? Explain why. a) An election pollster used convenience sampling to determine the favourite party in a national election. b) A school principal asked to grade 10 students their opinions on the grade 10 literacy test. c) To determine the reading level of books used in a particular school board's English literature classes, two classes at two schools were selected at random and their books were assessed