Can someone help me understand this?

A)  

Step-by-step explanation:

OK so if a figure is a dilation of another figure that means that is has the same angles but the sides are going to be smaller or bigger. Even though the sides are a different size they are proportional. So if I divided the length of AB over XY I'd get 5 since that is the scale factor. If I did that with AC over XZ I'd get 5 again because that is the scale factor. That's because they were proportional. Let's say this wasn't a dilation and AB over XY was 5 but AC over XZ was 4 that would mean it isn't proportional because AB would be 5 times bigger but XZ is only 4 times bigger.

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.