Question

2. Which is true of the human circulatory

system?

A It transports oxygen and nutrients.

B It makes blood cells.

C It breaks down food and releases nutrients.

D It is the first line of defense against pathogens.

Answer 1

I saw an answer that said B, but that is INCORRECT. Bones actually make the blood, in which bones are not apart of the circulatory system. Meaning that it is actually D. The circulatory system includes cells such as Blood Cells, and White Blood Cells. White Blood Cells defend the blood stream from any PATHOGENS or bad bacteria invading.

Therefore, the answer is in fact D!

Answer 2

Answer: B

Step-by-step explanation:

The circulatory system includes the heart, veins, arterioles, etc.. Includes blood as well