"Comparisons Between Cells That a Researcher Has Planned to Perform

Multiple Choice

"Comparisons between cells that a researcher has planned to perform prior to a study being conducted.These constitute a subset of all possible comparisons and have usually been identified as important on the basis of a particular theory." What is this a glossary definition of?

A) Restricted comparisons.
B) Proper comparisons.
C) Post hoc comparisons.
D) Ad hoc comparisons.
E) A priori comparisons.