When Would It Be Appropriate to Use the Planned Comparisons

Multiple Choice

When would it be appropriate to use the planned comparisons instead of the post hoc tests to identify differences in the time-trial groups?

A) When specific hypotheses have been generated before the experiment.
B) Comparisons should always be run with post hoc tests.
C) Comparisons should be run in place of post hoc tests when no hypothesis has been planned prior to the experiment.
D) Neither post hoc tests or comparisons are really necessary, as they only provide supplementary information.