This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
The Vitamin A activity of beta-carotene compared to that of retinol is? 
Select and explain. 
A. 2-Jan, B. 4-Jan, C. 6-Jan, D. 8-Jan
C: 6-Jan
Answer: C: 6-Jan 
Explanation: Beta-Carotene (provitamin A): 

This is found in plant foods. lt is cleaved in the intestine to produce two moles of  retinal.
ln humans, this conversion is inefficient, hence beta-carotene possesses about  one-sixth vitamin A activity compared to that of retinol.

Reference: Satyanarayana- Biochemistry, 3rd edition, pg-119