Hi,
I see, all you need to do is when you press the button, you change which input variable you read to your output.
I would say "which sensor is active" is a bad choice of words.
Go back to your teacher/instructor and get clarification.
Tom... 
Hi,
I see, all you need to do is when you press the button, you change which input variable you read to your output.
I would say "which sensor is active" is a bad choice of words.
Go back to your teacher/instructor and get clarification.
Tom...