Not tested but some nested if statements loops may work on thenevery frame tab in the code component
if t <= 4.0:
if t<= 2.0:
if len(theseKeys) == 2: #however many responses you need - in your example it has to be less than or equal to 2 which will
always be true
continueRoutine = False
if len(theseKeys) == 2:
continueRoutine = False
else:
continueRoutine = False