Refer to the Normal-Form Game of Price Competition Shown Below

Multiple Choice

Refer to the normal-form game of price competition shown below. $\begin{array}{l}\quad\quad\quad\quad\quad\quad\text { Firm B}\\\text { Firm A}\begin{array}{|l|l|l|} \hline & \text { C } & \text { D }\\\hline & & \\ \text { A } & 50,50 & 500-x, 200 \\\hline & & \\\text { B } & 100,500-x & 50,50 \\\hline\end{array}\end{array}$ For what values of x is strategy (B,D) the only Nash equilibrium of the game?

A) All x > 450
B) All x < 450
C) x = 450
D) x < 50