Answer:
d. our populations of radishes were small
Step-by-step explanation:
Natural selection is a type of evolution that allows only individuals with favorable characteristics and better adapted to the environment to survive and reproduce offspring with the same favorable characteristics. In this case, to observe a population where natural selection is taking place, population sizes can be disregarded, as this is not a condition for natural selection to take place. However, the other conditions presented in the response options are necessary for natural selection, since it is necessary that there are different phenotypes and genotypes in the population and that competition between them promotes the survival of one group at the expense of the other.