To solve the equation \( ?% \times 20 = 4 \), we can first rewrite it in mathematical terms.
Let \( x \) be the percentage we are looking for:
\[ \frac{x}{100} \times 20 = 4 \]
Now, simplify the equation:
\[ \frac{20x}{100} = 4 \]
This can be further simplified by multiplying both sides by 100:
\[ 20x = 400 \]
Now, divide both sides by 20:
\[ x = \frac{400}{20} = 20 \]
Therefore, the percentage \( x \) is 20%.
So the answer is A. 20%.