A new species is formed when:

A.An individual with a new genotype is formed due to exchange of chromosome segments during crossing over in gametogenesis
B.Genotypic changes accumulates in a population resulting in its reproductive isolation from other populations
C.Variants with new phenotypes are produced due to new combination of genes during reproduced due to new combination of genes during reproduction
D.Homologous chromosomes exchanges segments during crossing over

De Vries Theory of Organic Evolution is longer accepted because of one of the lowing criticisms:

A.Oenothera Lamarckiana is highly inconsistent hybrid species and distribution of 14 chromosomes is highly anamolous
B.Mutants often render mutants so much different from other members of species that they fall to compete and perish
C.Being random, the mutations are hardly useful in adaptability, therefore, they bring extinction of species rather than evolution
D.All of these