"If a Theory Is True, Then Event X Should Occur

"If a theory is true, then event X should occur." Which of the following outcomes illustrates the fallacy of affirming the consequent?

A) event X occurs, therefore the theory has been proven true
B) event X occurs, therefore the theory has been supported
C) event X does not occur, therefore the theory has been disproven
D) event X does not occur, therefore the theory has not been supported