Distance between points A-B

A= (-1, 1)
B= (3, 1)

1,1-3,1=2

so I think 2,0

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.  

what i would say the best answer is a. 40.5