Explanation:

- The large sphere has a radius of 9 cm.

- The volume of the large sphere is calculated as: \(V = \frac{4}{3} \pi r^3 = \frac{4}{3} \pi (9)^3 = 972 \pi \, \text{cm}^3\).

- Each small sphere has a radius of 2 cm.

- The volume of each small sphere is: \(v = \frac{4}{3} \pi r^3 = \frac{4}{3} \pi (2)^3 = \frac{32}{3} \pi \, \text{cm}^3\).

- To find the number of small spheres: divide the volume of the large sphere by the volume of a small sphere: \(\frac{972 \pi}{\frac{32}{3} \pi} = \frac{972 \times 3}{32} = 91.125\).

- Since you can't have a fraction of a sphere, you round down to 91.

- Options:

- Option 1, 92: Too high.

- Option 2, 90: Too low.

- Option 3, 93: Too high.

- Option 4, 91: This is the correct number.

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