This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Biochemistry
Which of the following does not dependent on insulin GLUT4 for glucose uptake? 
Select and explain. 
A. Brain, B. Skeletal muscles, C. Cardiac muscle, D. Adipose tissue
A: Brain
Answer: A: Brain 
Explanation: Tissue-like brain is still able to impo glucose from the serum through maintaining a basal level glucose receptors on the cell surface.The general picture is as follows :Glucose is hydrophilic and cannot cross cell membrane most cell have membrane proteins that can shuttle glucose from one side to otherRef: DM Vasudevan, 7th edition, page no: 318