The Following Payoff Matrix Shows the Outcomes for the US

The following payoff matrix shows the outcomes for the US and the USSR from relying on conventional weapons or atomic weapons.The percentages refer to the fraction of the population that would die if a war occurred under the two weapons strategies.Assume the payoff matrix is for 1945,shortly after the US had demonstrated the effectiveness of the atomic bomb in World War II,i.e. ,the example begins in the upper right cell where USA has atomic weapons and the USSR has only conventional weapons. $\begin{array}{c}\quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \quad \text { USSR }\\\text { USA }\begin{array}{|l|l|l|}\hline& \text {Atomic Weapons } & \text { Conventional } \\\hline \text { Atomic } & \text { In the USA, } 60 \% \text { would die, } & \text { In the USA S\% would die, } \\ \text { Weapons } &\text { In the USSR, } 60 \% \text { would die } & \text { In the USSR, } 90 \% \text { would die } \\\hline \text { Conventional } &\text { In the USA, } 90 \% \text { would die; } & \text { In the USA } 10 \% \text { would die, } \\\text { In the USSR, } 5 \% \text { would die } & \text { In the USSR, } 10 \% \text { would die.. } \\\hline\end{array}\end{array}$
Refer to the information given above.When the United States demonstrated its nuclear capability in the 1940's,the predictable result was:

A) the arms race ended.
B) the USSR responded by developing chemical weapons.
C) the USSR developed its nuclear capability.
D) the United States decided to refrain from development.