Okay... A vs E please

That's extremely common on Strengthen with a Sufficient Premise question! The correct answer needs to connect the premises to the conclusion. He conditional statement will typically look like: "premise --> conclusion." In this case, that would look like "do not know if action is legal --> do not feel secure." (A) reverses and negates this claim, so it is the contrapositive. (E) and (C) and (D) either just reverse or just negate that claim.