The author never suggests that she values a company’s ability to monitor emails. So there’s no basis to think the author would agree with (A) regarding the single-keystroke system.

This best captures what the author is likely to agree with. She said only one thing about encryption — scrambling one’s own messages with an encryption code is likely to undermine convenience. This is evidence that the author thinks a method of encryption that doesn’t involve having to scramble one’s own code is probably more convenient (and hence, reduce the difficulty of protecting one’s emails).

The author never suggests that encryption might create legal problems for companies that are trying to prevent employees from revealing secrets. There’s simply no connection presented in the passage between encryption and attempts to prevent employees from revealing trade secrets.

It’s not clear why a single-keystroke method of encryption would guarantee “only a minimal level of employee privacy.” Even if it doesn’t guarantee absolute privacy, it might still guarantee a substantial amount of privacy. In any case, the author doesn’t express an opinion about whether implementing encryption is “worth” the cost. We have no reason to think the author wouldn’t favor installation of the single-keystroke system.

The author doesn’t connect encryption with the legal definition of a “reasonable expectation of privacy.” We have no reason to think the single-keystroke method would affect the legal definition.