Why do some combinations of chromosomal centric fusions cause problems in meiosis?

Because centric fusions modify the chromosome number

Explanation:

The centric fusion is a translocation that involves acrocentric chromosomes. During cell division, pairs of homologous chromosomes are aligned on the equatorial plane and subsequently they move to opposite poles in the cell.

true is the answer : )

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."