Answer: Oblique impact
Explanation:
When the motion of one or both of the particles is at an angle to the line of impact, the impact is said to be oblique impact.
On the other hand, when the directions of motion of the two colliding particles are moving along a line of impact, then it's refered to as central impact.
The answer is A. When the forces are weaker, they will not be able to hold the particles of the substances together; therefore, the substance will be observed as being volatile.