Option B is the correct answer.

When the masses of two objects is doubled, the gravitational force between these objects increases by four times.

Using the formula:

$$F = G \cdot \dfrac{m_1 \cdot m_2}{d^2}$$

When $m_1' = 2m_1$ and $m_2' = 2m_2$,

$$F' = G \cdot \dfrac{2m_1 \cdot 2m_2}{d^2}$$

$$F' = 4 \cdot G \cdot \dfrac{m_1 \cdot m_2}{d^2}$$

$$F' = 4 \cdot F$$