Ann is opening a new savings account with an initial deposit of $250. which combination of a deposit and a withdrawal will result in a zero balance in ann's account?
a) deposit $20 in the first week and withdraw $270 in the second week.
b) deposit $270 in the first week and withdraw $20 in the second week.
c) deposit $20 in the first week and withdraw $250 in the second week
d) deposit $250 in the first week and withdraw $20 in the last week.
i don't get this pls !

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.  

really your just stupid if you don't know this

step-by-step explanation: