Use the Following Information to Answer the Question $\begin{array}{l}H_{0}: \text { median }=0 \\H_{A}: \text { median } \neq 0\end{array}$

Use the following information to answer the question. Can stretching help you stay alert in class? Thirty-six subjects were
measured for alertness at the beginning of class; the subjects then participated in some light arm and neck stretches followed
by a forty-five minute lecture. Each subject was then measured for alertness at the end of the lecture. The hypothesis test
results for the sign test are summarized below. Assume that all conditions for testing have been met: Hypothesis test results:
Parameter: Median of variable
$\begin{array}{l}H_{0}: \text { median }=0 \\H_{A}: \text { median } \neq 0\end{array}$
$\begin{array}{|l|l|l|l|l|l|l|l|}\hline \text { Variable } & \mathrm{n} & \mathrm{n} \text { for tests } & \text { Sample Median } & \text { Below } & \text { Equal } & \text { Above } & \text { P-value } \\\hline \text { Difference } & 36 & 32 & 1 & 12 & 4 & 20 & 0.2153 \\\hline\end{array}$
-What is the name and value of the test statistic?

A) $Z=12$
B) $\mathrm{F}=20$
C) $S=20$
D) $S=12$