Ideally, stress testing should be carried out in a:

A.
test environment using test data.

B.
production environment using live workloads.

C.
test environment using live workloads.

D.
production environment using test data.

Explanation:
Stress testing is carried out to ensure a system can cope with production workloads. A test environment should always be used to avoid damaging the production environment. Hence, testing should never take place in a production environment (choices Band D), and if only test data is used, there is no certainty that the system was stress tested adequately.