A population of short-finned fish and a population of long-finned fish live in a lake. Fish with long fins swim faster than fish with short fins, which means they escape predators more often. According to natural selection, which of the following will happen over time?

a. The number of long-finned fish will increase.
b. The number of long-finned fish will decrease.
c. The number of short-finned fish will increase.
d. The number of short-finned fish will not change.