Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

In the step "stating a decision rule" in testing a hypothesis, which of the following elements must be specified?
Option A:Critical value
Option B:Power of a test
Option C:Value of a test statistic

Answer: A