I believe the answer is DNA
Answer: Temperature control
Explanation:
Arterio-venous anastomoses (AVAs) are direct connections between small arteries and small veins. In humans they are numerous in the glabrous skin of the hands and feet.
They are very significant in body temperature control. These temperature control are under the dual control of the central nervous system and the local thermal influence. While the arteriovenous anastomoses control the skin temperature through volume changes in the superficial venous bed, the arterioles and capillaries operate by generalized dilatation which results both in increased temperature and in redness of the skin.
The answer to your question is C!
Correct answer: A). Root
The part of the word that can not be broken down is called root word. In the word claustrophobic ''phob'' is the root word. It can not be suffix as a suffix are added after the root word. It cannot be prefixed as it is added before the root word. Here the prefix would be ''claustro'' and suffix would be ''ic''. It cannot be affixed as it contains both suffix and prefix.
Hence, the correct answer would be option A.