Whenever the sperm and the egg combine, it is possible for one or the other to not split properly and bring 2 of the chromosomes instead of just 1
The correct option is C.
Science is a dynamic subject and it changes all the time. In the science field, research is always on going and when new evidence are discovered about a particular topic, the new evidence are usually used to update the scientific information that is already on ground. All the areas of science listed about have enjoyed scientific updates in the recent past.