Correct Answer: (A) Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of Assertion (A).

Step 1 - Check the Assertion:

True. During colonial rule the British labelled certain communities as 'martial races' fit for the army, and dismissed others as effeminate, cowardly or untrustworthy.

Step 2 - Check the Reason:

True. A stereotype is a fixed and inflexible image applied to a whole group of people, ignoring the differences between individuals within it.

Step 3 - Check the link:

The labels given in the Assertion are exactly such fixed group images. The definition in the Reason therefore explains what those labels were.

Hence, option (A) is correct.