- When \( n \) equal resistors each of resistance \( R \) are connected in series, total resistance is:
\[
R_{\text{series}} = nR,
\]
which is the maximum resistance.
- When connected in parallel, total resistance is:
\[
R_{\text{parallel}} = \frac{R}{n},
\]
which is the minimum resistance.
Therefore, the ratio is:
\[
\frac{R_{\text{max}}}{R_{\text{min}}} = \frac{nR}{\frac{R}{n}} = n^2.
\]
Note: The ratio is \( n^2 \), so correct answer should be (D).