Because reference type variables are the means by which we access objects, a reference type variable is sometimes called a(n) ____.

A company hires a consulting firm to crawl its Active Directory network with a non-domain account looking for unpatched systems. Actively taking control of systems is out of scope, as is the creation of new administrator accounts. For which of the following is the company hiring the consulting firm?

A. Vulnerability scanning B. Penetration testing C. Application fuzzing D. User permission auditing

There are ______ types of protocols used for transferring email.

A. two B. four C. six D. three