Why is it now a challenge to use phone numbers for drawing a simple random sample?

a. some people only have cellphones
b. some people have cellphones and landlines, so could be called twice
c. phone numbers are now portable so area codes do not always correspond to location
d. all of the above

i believe the answer is the polygon, heptagon.

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.  

jwjeh; hw; kjhekjhkjhwkejhkw

step-by-step explanation: