Which sentence from "Yellow Fever" can be defined as an effect? Although scientists are not certain where and when yellow fever began, they believe the first cases were in Africa. Not all mosquitoes carry this disease, and some mosquitoes actually get it from biting an infected person. The next stage can include high fever, internal bleeding, unconsciousness, and harm to the heart, liver, and kidneys They believed that yellow fever was spread by germs from unclean air or contact with dirty linen.

C. The next stage can include high fever, internal bleeding, unconsciousness, and harm to the heart, liver, and kidneys

Explanation:

"Cause" is the reason why something happened. "Effect" is the result of that action occurring.

Here, look at the answer choices:

A. "Although scientists are not certain where and when yellow fever began, they believe the first cases were in Africa."

Scientists think the cause of the yellow fever was in Africa, so this isn't effect. Eliminate A.

B. "Not all mosquitoes carry this disease, and some mosquitoes actually get it from biting an infected person."

How mosquitoes get this disease is the cause, so eliminate B.

C. "The next stage can include high fever, internal bleeding, unconsciousness, and harm to the heart, liver, and kidneys."

This is the effect of contracting the yellow fever, so C is correct.

D. "They believed that yellow fever was spread by germs from unclean air or contact with dirty linen."

This is how the yellow fever was spread, or its cause, so D is wrong.

The answer is C.

C. The next stage can include high fever, internal bleeding, unconsciousness, and harm to the heart, liver, and kidneys.