Which method recommends that very frequent system builds should be carried out with automated testing to discover software problems ?

Which method recommends that very frequent system builds should be carried out with automated testing to discover software problems ?

A. Agile method
B. Parallel compilation method
C. Large systems method
D. All of the mentioned

Explanation: In keeg with the agile methods notion of making many small changes, continuous integration involves rebuilding the mainline frequently, after small source code changes have been made.