Here's a problem to solve: Which of the following actions will increase the gravitational force between two masses, m_{1} and m_{2}, by the greatest amount?

Among the 4 following options, which is the correct answer?

- A: Halve the mass of m_{1} and halve the distance between m_{1} and m_{2}.
 
- B: Halve the mass of m_{1} and double the distance between m_{1} and m_{2}.
 
- C: Double the mass of m_{1} and halve the distance between m_{1} and m_{2}.
 
- D: Double the mass of m_{1} and double the distance between m_{1} and m_{2}.
 