During an audit of a telecommunications system, an IS auditor finds that the risk of intercepting data transmitted to and from remote sites is very high. The MOST effective control for reducing this exposure is:

A. encryption.

B. callback modems.

C. message authentication.

D. dedicated leased lines.

Explanation:

Encryption of data is the most secure method. The other methods are less secure, with leased lines being possibly the least secure method.