Mad cow disease has received a lot of news attention lately. It is a brain disease in cattle. It causes odd behavior, difficulty walking, and eventually death. Scientists believe this disease came about recently. It comes from feeding cattle extra vitamins that have parts from sick sheep.

What is the main idea of this paragraph?

A.
Scientists think a cattle disease has received increased attention.
B.
Mad cow disease affects cattle after they eat infected vitamins.
C.
Mad cow disease causes odd behavior, difficulty walking, and death.
D.
Parts from sick sheep can sometimes be included with extra vitamins