Which of the following is not a fat soluble vitamin?

Fat-soluble vitamins are basically similar to oil and they do not dissolve in water.  Vitamin A, D, E, K are the known fat soluble vitamins. 

Vitamin B complex is not a fat soluble vitamin because it is water soluble. It is a pack of all eight vitamins i.e vitamin B1, B2, B3, B5, B6, B7, B9 and B12.  As it is water soluble our body doesn't store it and hence the body must be served daily with vitamin B complex.

Final answer : So the correct answer is  option B.