Usability is _____.

a debugging technique that uses print statements to trace the program flow
a debugging technique that uses print statements to trace the program flow

the degree to which a program meets the needs of a user, including but not limited to learnability, reliability, and ease of use
the degree to which a program meets the needs of a user, including but not limited to learnability, reliability, and ease of use

a testing method that uses a program that tests another program
a testing method that uses a program that tests another program

conforming to accepted standards of behavior
conforming to accepted standards of behavior