Consider the Following to Answer the Question(s) Below

Consider the following to answer the question(s) below.
ASW, a regional shoe chain, has recently launched an online store. Sales via the Internet have been sluggish compared to their brick and mortar stores, and management suspects that its regular customers have concerns regarding the security of online transactions. To determine if this is the case, they plan to survey a sample of their regular customers.
-Suppose that ASW's regular customers belong to a rewards program and have a customer rewards ID number. ASW decides to randomly select 100 numbers. This sampling plan is called

A) Simple Random Sampling
B) Stratified Sampling
C) Cluster Sampling
D) Systematic Sampling
E) Convenience Sampling