**Explanation:**

When two bodies of different masses are acted upon by the same force for the same time, they will acquire different velocities, but their momentum will be the same.

**Velocity:**
The velocity of an object is directly proportional to the force applied on it and inversely proportional to its mass. Therefore, when the same force is applied to two bodies of different masses, the body with a smaller mass will experience a greater acceleration and acquire a higher velocity than the body with a larger mass. This is because the smaller mass requires less force to accelerate compared to the larger mass.

**Momentum:**
Momentum is defined as the product of an object's mass and its velocity. Mathematically, momentum (p) is given by the equation p = mv, where m is the mass of the object and v is its velocity. When the same force is applied to two bodies of different masses, both bodies will experience the same acceleration. However, since the smaller mass has a higher acceleration, it will acquire a higher velocity than the larger mass. But since the larger mass has a greater mass, it will acquire a lower velocity. Therefore, even though their velocities are different, their momentum will be the same. This is because the increase in velocity for the smaller mass is compensated by the decrease in velocity for the larger mass.

**Conclusion:**
In conclusion, when two bodies of different masses are acted upon by the same force for the same time, their velocities will be different, but their momentum will be the same. This is because the smaller mass will experience a greater acceleration and acquire a higher velocity, while the larger mass will experience a smaller acceleration and acquire a lower velocity. Therefore, the correct answer is option B - momentum.