Part a genetic variation occurs when chromosomes are shuffled in fertilization and what other process?

Variation also occurs during meiosis. When the sister chromatids line up, there can be some shuffling that takes place. During the crossing over phase, some of the DNA can be shared or exchanged, and this can lead to variation that expands the range of genetic possibilities.

Ichoose a as my answer

Hmmm i'm not sure about this one