A) S
B) R
C) T
D) Q

Multiple Choice

$$\begin{array}{l}\text { Use the system shown to find } s * s \text {. }\\\begin{array} { c | c c c c } * & q & r & s & t \\\hline q & t & s & r & q \\r & s & q & t & r \\s & r & t & q & s \\t & q & r & s & t\end{array}\end{array}$$

A) s
B) r
C) t
D) q