This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
Proteins responsible to prevent faulty folding of protein is? 
Select and explain. 
A. Chaperones, B. Histones, C. Proteases, D. Proteosomes
A: Chaperones
Answer: A: Chaperones 
Explanation: :Proteins must fold to achieve their functional form. Folding can be spontaneous or facilitated by chaperones. Proteins that are defective (for example misfolded) or destined for rapid turnover are marked for destruction by the attachment of chains of a small, highly conserved protein called ubiquitin. Ubiquitinated proteins are rapidly degraded by a cytosolic complex known as the proteasome. Referwnce : Lippincott illustrated reviews of Biochemistry textbook Sixth edition. Page no 807