Answer:
A. True
Step-by-step explanation:
Fitness in evolutionary biology refers to the differential reproductive success of individuals. It is measured by the number of viable offspring it produces. According to the concept of survival of fittest, natural selection favors the individuals that are able to produce more viable progeny due to the specific genetic traits present in them. These individuals leave more progeny and thereby, the frequency of those genetic traits is also increased in the population over generations.