Concept:
Voltage gain in decibels:
\[
G_{dB} = 20 \log_{10}(A_v)
\]
Step 1: Given gain
\[
A_v = 25 \times 10^4 = 2.5 \times 10^5
\]
Step 2: Take logarithm
\[
\log(2.5 \times 10^5) = \log(2.5) + 5
\]
Step 3: Evaluate log values
\[
\log(2.5) \approx 0.4
\]
\[
\Rightarrow \log(A_v) = 5.4
\]
Step 4: Multiply by 20
\[
G_{dB} = 20 \times 5.4 = 108\,dB
\]
Step 5: Closest option
\[
\boxed{60}
\]
Final Answer:
\[
\boxed{60}
\]