Which of the following is NOT a valid use of decision coverage?

Which of the following is NOT a valid use of decision coverage?
A . Checking that all decisions have been exercised in a single program
B . Checking that all decisions have been exercised in a business process
C . Checking that all calls from one program module to another have been made correctly
D . Checking that at least 50% of decisions have been exercised by a test case suite

Answer: D