DSST Practice Exam Question

[journey]

I went to the getcollegecredit.com site and ordered the practice test for Environment and Humanity. The score report listed the questions that I got incorrect but the rationale did not give me the correct answer in order for me to study with. For those that have taken these tests, am i missing something? At least the Peterson's tests lets you know the ones you got wrong and proceeds to give the correct answer with explaination. For example: the question would be "An oligotrophic lake is one that....., My response was: "is rich in nutrients". The rationale just stated "By definition. All but correct answer refer in some manner to eutrophied lakes". Well, since we no longer have access to all of the other answers, the rationale really doesn't mean much. I hope i've explained this and maybe someone out there can tell me how they used this tool to study.

Signed,
Desparate Journey