Answer the Question on the Basis of the Following Production

Answer the question on the basis of the following production possibilities data for Gamma and Sigma.All data are in tons. Gamma's production possibilities: $\begin{array}{llcc}&\underline{\text { A } }&\underline{\text {B}}&\underline{\text { C} } &\underline{\text { D } }&\underline{\text {E}}\\\text { Tea } &120&90&60&30&0\\\text { Pots}&0&30&60&90&120\end{array}$
Sigma's production possibilities: $\begin{array}{llcc}&\underline{\text { A } }&\underline{\text {B}}&\underline{\text { C} } &\underline{\text { D } }&\underline{\text {E}}\\\text { Tea } &120&90&60&30&0\\\text { Pots}&0&30&60&90&120\end{array}$
Refer to the given data.Assume that before specialization and trade,Gamma and Sigma both chose production possibility "C." Now if each specializes according to comparative advantage,the gains from specialization and trade will be:

A) 40 tons of pots.
B) 20 tons of tea and 20 tons of pots.
C) 20 tons of tea.
D) 40 tons of tea.