The answer could be C. However I would double check.
“Chromosomes carry genetic information in a molecule called DNA. A type of cell division called mitosis ensures that when a cell divides each new cell produced has the same genetic information. DNA exists in a cell's nucleus within structures called chromosomes .”
The correct answer is d. Robertsonian translocation.
The translocation can be defined as the chromosomal rearrangement, which takes place between two non homologus chromosomes. In the Robertsonian translocation a fragment of the chromosome is replaced with the fragment of another chromosome. In this way, the Robertsonian translocation result in structural abnormality in two chromosomes.
I believe the correct response is D. Need a living host cell to reproduce.
I believe the answer is delta.