HELLLP this is confusing

What role does differential reproduction play in natural selection? ! a) some organisms have different reproductive success due to nongenetic traits. b) some organisms have traits that them reach reproductive age. c) different methods of reproduction result in some organisms being genetically altered. d) reproduction varies among organisms due to pathogenic factors. the answer is not a or d based on other posts.

Which mantle is under the crust the upper mantle or the lower mantle i think it's upper let me know if i'm right

Which is the correct first step in finding the area of the base of a cylinder with a volume of 26x cubic meters and a height of 6.5 meters? v=bh 6.5=b(26x) v=bh v=26pi+(6.5) v=bh v=26pi(6.5) v=bh 26pi=b(6.5)