Final answer:
A dog is more closely related to a cat than a frog on a cladogram because both dogs and cats are mammals and share a more recent common ancestor compared to amphibians like frogs.the right answer is A
Step-by-step explanation:
The question is asking about the interpretation of a cladogram, which is a diagram that depicts the evolutionary relationships among groups of organisms. On a cladogram, organisms that are more closely related will share a more recent common ancestor, and will thus be placed closer together. Given the information provided about similarities in evolutionary traits and ancestry, such as the presence of amniotic eggs and the derived trait of leg absence in marine mammals, it is evident that on the scale of evolutionary relatedness, a dog would be more closely related to organisms within the same or similar higher taxonomic groups.
Accordingly, between the options provided, a dog, being a mammal, is more closely related to a cat than to a frog, which is an amphibian. This is because both dogs and cats are within the mammalian clade, while frogs are not. Answer A is correct: A dog is more closely related to a cat than a frog.