The center of gravity is a point inside a mass where the weight of the mass is considered to act on. And the center of gravity of an object can change position if you add more mass on certain areas of the object. So lets say you have a vehicle and the vehicle has the center of gravity right in the middle (this means at mid-height, mid-length and mid-width). Now you put some stuff on the trunk, well guess what? The center of gravity now shifted some towards the trunk of your car. And if you didn´t place the extra mass right in the middle of the trunk, the you also moved the center of gravity to whatever side you put the mass on.
In regards of the other three options:
Force of impact has nothing to do with center of gravity. Although if you want to be very strict, if you crash and the force of impact deforms your car so much that the vehicle has now a totally different shape, then yeah, all the rearrangement of the mass will move the center of gravity from its initial position. But for the scope of this question, the answer is NO.
The antilock brakes or ABS have nothing to do with center of gravity. All they do is prevent your car from sliding by keepin the tires rotating when you slam on the brakes.
Torque has nothing to do with center of gravity. More torque will help you with acceleration of your vehicle.
Loading determines the weight and/or the center of pressure on a vehicle. Center of gravity refers to the whole weight of the load acting with its orientation. Loading affects the center of gravity as the object is positioned and balanced on the vehicle.
