Again, I am unsure about this one because it seems to be very poorly phrased in terms of grammar. I believe the answer should be VALID, it's just not phrased correctly?
In any event, any help or feedback would be greatly appreciated.
"IF A HAPPENS, THEN B HAPPENS.
B DOES NOT HAPPEN.
THEREFORE A DOES NOT HAPPEN."
[valid/invalid why]?
I gave you the validation in your last post. This is an example of a statement and its contrapositive. If the statement is true, then the contrapositive is true. Look at the other post. And look here: Logic - Contrapositive