Which of these “properties” of testing using stubs and drivers are correct?

a) Using drivers and stubs is a lot of work for not much gain.
b) Using drivers and stubs avoids trying to debug a large program all at once.
c Testing the pieces is difficult to do in any significant way. You need the entire program to run a meaningful test.
d) Drivers run the pieces individually. They are temporary. They can be minimal, without i/o, having only data generating code, and not doing much (except possibly validating) with the information they return.
e) Stubs are short programs that are fairly easy to write. They return only minimum data necessary for the caller to be debugged.

b) Using drivers and stubs avoids trying to debug a large program all at once.
d) Drivers run the pieces individually. They are temporary. They can be minimal, without i/o, having only data generating code, and not doing much (except possibly validating) with the information they return.
e) Stubs are short programs that are fairly easy to write. They return only minimum data necessary for the caller to be debugged.

This testing technique is essentially divide and conquer. You avoid testing a large program all at once, allowing the testing of the i/o routines, for example, with drivers to assure that they work properly.