Answer: D
Let \(x\) be the number of spheres that can be made. \[ \therefore \frac{4}{3}\pi \cdot 2^3 \cdot x = \frac{1}{3}\pi \cdot 20^2 \cdot 10 \Rightarrow 4 \cdot 8x = 400 \cdot 10 \Rightarrow x = \frac{4000}{32} = 125 \therefore \text{125 solid spheres can be made.} \]
Let \(x\) be the number of spheres that can be made. \[ \therefore \frac{4}{3}\pi \cdot 2^3 \cdot x = \frac{1}{3}\pi \cdot 20^2 \cdot 10 \Rightarrow 4 \cdot 8x = 400 \cdot 10 \Rightarrow x = \frac{4000}{32} = 125 \therefore \text{125 solid spheres can be made.} \]