Which of the Following Describes an A-B-A Design

Multiple Choice

Which of the following describes an A-B-A design?

A) There is a baseline measurement, then a treatment and a posttest, and then a return to baseline.
B) There is a baseline measurement, then a treatment, and finally a posttest.
C) There is a treatment and a posttest.
D) There is a baseline measurement, then a treatment and posttest, then a return to baseline, then a reintroduction of the treatment and another posttest.