Answer:
The correct option is C) 1 only
Step-by-step explanation:
It would be necessary to ask from the scientist about the group of people on which he performed his experiment because it might be that certain other factor was the influence for the change in the requirement of Vitamin E, It might be that the people of that specific area or country might have a Vitamin E deficiency due to which there requirement was more for Vitamin E. Or there might be any other environmental or genetic factor influencing the change.