By the way, the reason that that is the credited answer is because it satisfies the antecedent (sufficient condition) and falsified the consequent (necessary condition). This is exactly what must be so if material conditionals are false.
I found a huge improvement when I quit trying to find the specific flaw and simply started by reading the stim and identifying what was wrong, then going to the answers to find it there. Fit the answers to the prepphrase!
... same skills. You're basically identifying the premise + conclusion and figuring ... lessons on those and practice identifying the parts of each argument ...