To determine the opportunity cost for the United States to produce corn, we need to understand the concept of opportunity cost, which is typically calculated as the ratio of what is given up to what is gained.
Given the tabular data:
[tex]\[
\begin{tabular}{|c|c|c|}
\hline
Congo & 20 & 5 \\
\hline
\end{tabular}
\][/tex]
From this data, we observe 20 and 5 as relevant figures, which naturally form the ratio [tex]\( \frac{20}{5} \)[/tex] for Congo. The value of this fraction is [tex]\( \frac{20}{5} = 4 \)[/tex].
Now, we need to compare this with the given options to identify the fraction that represents the opportunity cost for the United States to produce corn:
1. [tex]\( \frac{60}{10} \)[/tex]
- Simplifying this fraction: [tex]\( \frac{60}{10} = 6 \)[/tex]
2. [tex]\( \frac{10}{60} \)[/tex]
- Simplifying this fraction: [tex]\( \frac{10}{60} = \frac{1}{6} \)[/tex]
3. [tex]\( \frac{20}{5} \)[/tex]
- Simplifying this fraction: [tex]\( \frac{20}{5} = 4 \)[/tex]
4. [tex]\( \frac{5}{20} \)[/tex]
- Simplifying this fraction: [tex]\( \frac{5}{20} = \frac{1}{4} \)[/tex]
Comparing these simplified values, we see that option 3 simplifies to 4, which matches the structure of the opportunity cost data for Congo.
Given this, the fraction that represents the opportunity cost for the United States to produce corn is:
[tex]\[ \frac{20}{5} \][/tex]
Thus, the correct answer is:
[tex]\[ \boxed{3} \][/tex]