Condition A in the table describes a population of tortoises where there are smaller adult tortoises and larger adult tortoises.
This condition represents competition. In a population where there is competition for resources like food, the tortoises that are smaller may struggle to find enough food and may be at a disadvantage compared to the larger tortoises. As a result, the larger tortoises may have a better chance of surviving and reproducing, passing on their genes for larger size to the next generation. This is an example of natural selection for the trait of size.
Condition B in the table states that food is scarce on the island where the population is present. This condition represents a limited resource. When resources like food are limited, there is a competition among individuals to obtain enough of that resource to survive and reproduce. In this case, the tortoises that are better adapted to finding and utilizing scarce food resources will have an advantage. These traits may be inherited from their parents. Over time, this can lead to natural selection for those traits that enable the tortoises to survive and reproduce in a food-scarce environment.
So, to summarize, Condition A represents competition, as there is competition between smaller and larger tortoises for resources. Condition B represents inherited variation, as the tortoises that are better adapted to the scarce food resources have an advantage due to their inherited traits.