Answer:
Yes, the data are sufficient but...
Explanation:
... only sufficient to conclude that rethinking and changing your answers has an impact on test scores. For example, if I think a little more maybe I come to a different conclusion on this very question I´m answering right now.
But the data given in this example are not sufficient to determine whether rethinking (and changing) hurts or helps.
Frankly I doubt it very much that you can determine such a thing because I feel that for some it will help and for others it will hurt.