Answer:
a,c,d
Explanation:
The formation of entirely new genetic materials from crossing over of genetic materials of the two parents at Late propahse 1 of meiosis ensures that the offspring have a different genetic composition for variation to occurs.
The independent assortment of genes ensures that random combination of different homologous chromosomes of diverse genetic composition produces offsipring with a new combination of genes different from both parents
The 4 genetically haploid cells produced by meiosis ensures that each new daughter cells has varied genetic composition, from half combination of genetic materiel;s from each parent,which can not exactly similar to another haploid cell.The eventual re-combination with another set of haploid chromosomes by random fertilization, gives an entirely different set of chromosomes combination to from new offspring, leading to variation