You and Dr. Cline are working with the facility's statistician to determine sample size. You are discussing which sampling method you will use. There are 1200 possible records and you need 100 records for the study. Dr. Cline suggests you select every 12th record until sample size is achieved. This makes sense to you. It takes less time and is less subject to error than other sampling methods. The two of you agree to use
a. random sampling
b. simple sampling
c. stratified random sampling
d. systematic sampling