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
Folding protein area) GLUT-1b) Calnexinc) Cytochrome 450d) Insulin receptore) Protein disulfide isomerase 
Select and explain. 
A. ab, B. ad, C. bc, D. be
D: be
Answer: D: be 
Explanation: Some Chaperones and Enzymes Involved in Folding that is Located in the Rough Endoplasmic Reticulum

BiP (immunoglobulin heavy chain binding protein)
GRP94 (glucose-regulated protein)
Calnexin
Calreticulin
PDI (protein disulfide isomerase)
PPI (peptidyl prolyl cis-trans isomerase)