Sympatric Speciation and Diploid Plants?

Can someone help me with this question? If there is an explanation as well that'd be great because I want to understand this. Thank you!

1. Sympatric speciation can occur when nondisjunction produces pollen and egg cells that are diploid. If these plants self-pollinate, a new tetraploid species can occur. Will it be able to breed with the original diploid plants?
Answer
      a. No, it is isolated from the original diploid plants by a prezygotic barrier.
      b. No, it is isolated from the original diploid plants by a postzygotic barrier.
      c. Yes, but only if it happens during the first generation.
      d. Yes, since the original plants have all of the same chromosomes, it is possible.
      e. No, but for another reason that was not given.