The answer is B and I need 20 characters so I am typing random words
The answer is; A gopher snake occupies a burrow made by the desert rat
Commensalism involves a relationship between two organisms where one benefits while the other is unaffected. In this case, the gopher snake gets from the burrow made by the desert sake. The desert rat is unaffected (does not benefit or lose) by this action by the snake.
<span>D.It has affected the fates of a space probe and a commercial airline flight.</span>
single-nucleotide polymorphism, I think this might be it. I hope it helps.