A good way to feel out which law this describes is to think about catching a fast ball versus a slow one.
When you catch a fast-moving cricket ball, its momentum has to drop to zero very quickly, meaning the rate of change of momentum is large, and correspondingly your hand feels a large force, it stings. Catch a gently thrown ball instead, and its momentum changes slowly, so the force felt is small. This everyday observation is exactly the relationship the statement in the question describes: force is proportional to how quickly momentum changes.
This proportional cause-and-effect relationship between applied force and the resulting rate of change of momentum is not something the first law addresses, since it only concerns force-free motion, and it is not a paired-body interaction either, which would be the third law. It is the defining quantitative content of the second law.
Therefore: \[ \boxed{\text{Newton's second law of motion}} \]