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
Level of glucose transpoers are reduced after overnight fast in which of the following cells? 
Select and explain. 
A. Liver cells, B. Brain cells, C. RBCs, D. Cardiac muscle
D: Cardiac muscle
Answer: D: Cardiac muscle 
Explanation: Insulin is needed for GLUT mediated uptake of glucose in skeletal muscle, cardiac muscle and adipose tissue(GLUT4). Expression of GLUT will be affected after an overnight fast in these cells. Brain cells, RBCs & hepatocytes do not require insulin for glucose transpo.