(E) provides the missing half of the argument. So whether the e-mail does or does not suggest to do something illegal, the e-mail doesn’t serve a purpose. Either the e-mail doesn’t offer legal protection, or the company doesn’t need legal protection.

(B) doesn’t tell us what happens if the e-mail does not suggest that people should do something illegal. So we don’t know whether the disclaimer might be able to serve a purpose in that situation.

(C) establishes that people might end up ignoring the disclaimer. But this doesn’t prove that the disclaimer serves no purpose when the e-mail doesn’t suggest doing something illegal. The disclaimer might still serve its purpose in that situation, even if there’s a potential people will ignore the disclaimer.

This doesn’t establish that the disclaimer serves no purpose if the e-mail doesn’t suggest that clients do something illegal. We already know that the disclaimer serves no purpose if the e-mail suggests something illegal. What matters is what happens if the e-mail doesn’t suggest something illegal.

This doesn’t establish that the disclaimer serves no purpose if the e-mail doesn’t suggest that clients do something illegal. We already know that the disclaimer serves no purpose if the e-mail suggests something illegal. What matters is what happens if the e-mail doesn’t suggest something illegal.