Answer:
Sheep B
Explanation:
As given;
Step 1: The nucleus was removed from the egg which was unfertilized and,
which is taken from sheep A, means that the egg was from sheep A.
Step 2 : The nucleus of a body cell which is taken from sheep B was then
inserted into this unfertilized egg which is taken from sheep A. Now the egg contain nucleus of sheep B.
Step 3 : The resulting cell containing nucleus of sheep B was then implanted into the uterus of
sheep C.
Step 4 : finally Sheep C gave birth to a sheep named sheep D.
Sheep B would be most genetically similar to sheep D, because the nucleus was taken from sheep B, and the sheep D is the new born which is formed from the nucleus of sheep B.