Select the correct answer.
Protein X is produced in the liver cells of the body. However, this protein is not produced within the intestine. Which statement best explains why?


A.The gene for protein X is present in the intestinal cells, but it is not expressed.
B.The gene for protein X is not present in the intestinal cells.
C.The gene for protein X is present in the liver cells, but it is not expressed.
D.The gene for protein X is not present in the liver cells.