What Must Happen to a Newly Made Polypeptide Before It

Multiple Choice

What must happen to a newly made polypeptide before it can be secreted from a cell?

A) It must be translated by a ribosome that remains free of attachment to the ER.
B) Its signal sequence must target it to the ER,after which it goes to the Golgi.
C) Its signal sequence must be cleaved off before the polypeptide can enter the ER.
D) Its signal sequence must target it to the plasma membrane,where it causes exocytosis.