When writing a validation program using independent programming, which two actions conform to good programming practices?

When writing a validation program using independent programming, which two actions conform to good programming practices?

(Choose two.)
A . Ensure the production program has been run prior to compare.
B . Delete subjects from the production side that are causing differences with the validation data set.
C . Copy statistical code directly from the SAP.
D . Copy statistical code directly from the production program.

Answer: A C