The marketing division at Apex Telecom consists of four people. Two of the four will be randomly selected to attend a sales conference at the end of the year. If we designate the four people in the division as W, X, Y, and Z, list all the equally likely samples of size two that you might choose if you use
a. Simple random sampling. (You should list six samples.)
b. Systematic random sampling from the alphabetical list. (You should list two samples.)