Cell Division, Genetics and Molecular Biology question

The following diagram outlines how the process of cloning a sheep was accomplished.

Animal Cloning
 

Cloning is the process of creating a genetically identical copy of another individual. With Dolly, an egg cell was removed from a donor and the nucleus was removed from the egg cell. Then cells from a sheep's mammary gland were removed from a second donor. One of the cells from the mammary gland was fused with the enucleated egg cell using an electrical pulse. The fused cell underwent cell division and at the embryo stage was implanted into a surrogate mother sheep. When Dolly was born she was an exact copy of the nucleus donor sheep.

The percentage of genetic material that the clone has in common with the donor cell sheep is approximately
Select one:
a. 25%
b. 100%
c. 0%
d. 50%