The word "carcinogenic" means most nearly the same as ______.

A．Because of science, most of the foods we eat today are contaminated.
B．It has caused a lack of information concerning the value of food.
C．As a result of scientific intervention, some potentially harmful substances have been added to our food.
D．The scientists have preserved the color of meats, but not of vegetables.

A．They preserve flavor in packaged foods.
B．They preserve the color of meats.
C．They are the objects of research.
D．They cause the animals to become fatter.