How can we keep n=0 when it is mentioned n is a positive integer, as far as I know in GRE 0 is neither positive nor negative.
Please explain Carcass.

Testing Cases
Since $n$ is a positive integer, let's test a few small values for $n$.

Case 1: $\(n=1\)$
- Quantity A: $\(\frac{1}{3^1}=\frac{1}{3}\)$
- Quantity B: $\(\frac{3}{7^1}=\frac{3}{7}\)$

To compare $\(\frac{1}{3}\)$ and $\(\frac{3}{7}\)$, we can find a common denominator (21):
- Quantity A: $\(\frac{1 \times 7}{3 \times 7}=\frac{7}{21}\)$
- Quantity B: $\(\frac{3 \times 3}{7 \times 3}=\frac{9}{21}\)$

Since $\(\frac{7}{21}<\frac{9}{21}\)$, in this case, Quantity $\(\mathbf{B}>\)$ Quantity $\(\mathbf{A}\)$.

Case 2: $n=2$
- Quantity A: $\(\frac{1}{3^2}=\frac{1}{9}\)$
- Quantity B: $\(\frac{3}{7^2}=\frac{3}{49}\)$

To compare $\(\frac{1}{9}$ and $\frac{3}{49}\)$, we can cross-multiply, which is equivalent to finding a common denominator $\((9 \times 49)\)$ :
- $\(1 \times 49\)$ vs. $\(3 \times 9\)$
- 49 vs. 27

Since $\(49>27\)$, in this case, Quantity $\(\mathbf{A}>\)$ Quantity $\(\mathbf{B}\)$.

zero is neither + nor - in general . It is neutral. In general not only on the gRE

Itis a general math concept

Even my answer is A but the answer mentioned above is D.
Like when I click on show answer it shows D.

Thye OA is D

My resoining if D also

Why for you is A sir ?