The use of a diverse sample of study participants in multiple sites might promote which of the following?
A. Replicability of the study
B. The ability to use randomization
C. The ability to use blinding as a strategy
D. The study's external validity

The studys external validity.

Explanation:

Sampling can be defined as the process through which individuals or sampling units are selected from the sample frame. The sampling plan of action needs to be specified in advance, given that the sampling method may affect the sample size estimation. Without a careful sampling plan the results derived from the study may be biased. Hence the need for diverse sampling inorder to promote the studies external validity.

what is the tax base for the sales tax?

it should be (usually ) 6%