Final answer:
Decision coverage is a measure of the 'if' statements in the code that are exercised with both the true and false outcomes.
Step-by-step explanation:
The correct description of decision coverage is (C) Decision coverage is a measure of the 'if' statements in the code that are exercised with both the true and false outcomes. It refers to the percentage of conditional statements in the source code that have been executed with both true and false inputs during testing.