This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
Which of the following protein is synthesized in free ribosome? 
Select and explain. 
A. Cytosolic proteins, B. Secretery proteins, C. Membrane proteins, D. None
A: Cytosolic proteins
Answer: A: Cytosolic proteins 
Explanation: The synthesis of all proteins begins in thecytosol (the nonpaiculate pa of the cytoplasm) . However, proteins that will finish their synthesis on the RER have a sequence of amino acids called the signal sequence because this series of amino acids acts as a signal. Ref satyanarayana 4e