Table 13 Shows the Hypothetical Trade-Off Between Different Combinations of Brushes

Table 1.3 shows the hypothetical trade-off between different combinations of brushes and combs that might be produced in a year with the limited capacity for Country X,ceteris paribus. Table 1.3
Production Possibilities for Brushes and Combs
$$\begin{array} { | l | c | c | r | r | } \hline \text { Combination } & \begin{array} { c } \text { Number of } \\\text { combs }\end{array} & \begin{array} { c } \text { Opportunity } \\\text { Cost(Foregone } \\\text { brushes) }\end{array} & \begin{array} { c } \text { Number of } \\\text { brushes }\end{array} & \begin{array} { c } \text { Opportunity Cost } \\\text { (Foregone combs) }\end{array} \\\hline \mathrm { J } & 4 & &0 & \text { NA } \\\hline \mathrm { K } & 3 & & 10 & \\\hline \mathrm { L } & 2 & & 17 & \\\hline\mathrm { M }& 1 & & 21 & \\\hline \mathrm { N } & 0 & \text { NA } & 23 & \\\hline\end{array}$$ On the basis Table 1.3,what is gained by producing at point M rather than point N?

A) 23 combs.
B) 21 combs.
C) 1 comb.
D) 2 combs.