Using pathname expansion (Sobell, page 150), list the files in the /usr/bin directory that have the characters ab anywhere in their names.

To help human readers understand why a method's statements are there, good programmers insert explanatory ____ into their methods.

A. behaviors B. actions C. comments D. conditions

_________ can be used to provide confidentiality, data origin authentication, connectionless integrity, an anti-replay service, and traffic flow confidentiality.

Fill in the blank(s) with the appropriate word(s).