Table 11 Shows the Hypothetical Trade-Off Between Different Combinations of Stealth

Table 1.1 shows the hypothetical trade-off between different combinations of Stealth bombers and B-1 bombers that might be produced in a year with the limited U.S.capacity,ceteris paribus. Table 1.1
Production Possibilities for Bombers
$$\begin{array} { | l | c | c | c | c | } \hline \text { Combination } & \begin{array} { c } \text { Number of B- } \\1 \text { Bombers }\end{array} & \begin{array} { c } \text { Opportunity } \\\text { cost(Foregone } \\\text { Stealth) }\end{array} & \begin{array} { c } \text { Number of } \\\text { Stealth Bombers }\end{array} & \begin{array} { c } \text { Opportunity cost } \\\text { (Foregone B-1) }\end{array} \\\hline \mathrm { S } & 0 & \text { NA } & 10 & \\\hline \mathrm { T } & 1 & & 9 & \\\hline \mathrm { U } & 2 & & 7 & \\\hline \mathrm { V } & 3 & & 4 & \text { NA } \\\hline\end{array}$$ In the production range of 7 to 9 Stealth bombers,the opportunity cost of producing 1 more Stealth bomber in terms of B-1s is

A) 0.
B) 3.
C) 0.5.
D) 2.