What is the most efficient method to create the control group?

A large target population spans multiple age groups. The Business Practitioner needs to create a control group with 10% from each age group.

What is the most efficient method to create the control group?
A . Use a query activity to query the target population and another query activity to obtain the desired control group. Then use an exclusion activity to get the exclusive target.
B. Modify the target population query to not include the control group.
C. Use a query activity to obtain the target population and send to a split activity to remove each age group with record count limitation set as random.
D. Use the out of the box control group functionality with Random Sampling and Data Grouping.

Answer: C