$\text { TABLE 11-2 }$ $\text { TABLE 11-2 }$

$\begin{array}{c}&\text { Firm B }\\\text { Firm A }&\begin{array}{l|cc} & \text { Cooperate } & \text { Cheat } \\\hline \text { Cooperat } & (30,30) & (10, x) \\\text { Cheat }& (x, 10) & (20,20) \\\end{array}\end{array}$
$\text { TABLE 11-2 }$ $\begin{array}{c}&\text { Firm B }\\\text { Firm A }&\begin{array}{l|cc} & \text { Cooperate } & \text { Cheat } \\\hline \text { Cooperat } & (30,30) & (10, x) \\\text { Cheat }& (x, 10) & (20,20) \\\end{array}\end{array}$
$\text { TABLE 11-2 }$
-Refer to Table 11- 2.If Firm A is indifferent between cheating or cooperating when Firm B chooses to cooperate,x must be equal to

A) 0.
B) 10.
C) 40.
D) 20.
E) 30.