Juan organizes the stamps in his collection by country and by the decade in which they were issued. The prices he paid for them at a stamp shop were: Brazil and France, 6 \phi each, Peru 4 \phi each, and
Number of Stamps by Decade
\begin{array}{|c|c|c|c|c|}
\hline
\textbf{Country} & \textbf{'50s} & \textbf{660s} & \textbf{'70s} & \textbf{'80s} \\
\hline
\text{Brazil} & 4 & 7 & 12 & 8 \\
\hline
\text{France} & 8 & 4 & 12 & 15 \\
\hline
\text{Peru} & 6 & 4 & 6 & 10 \\
\hline
\text{Spain} & 3 & 9 & 13 & 9 \\
\hline
\end{array}
Juan’s Stamp Collection Spain 5 \$ each. (Brazil and Peru are South American countries and France and Spain are in Europe.) How many of his European stamps were issued in the $'80$s?
Answer Choices
A. 9
B. 15
C. 18
D. 24
E. 42