Below are four statements describing protein translocation into the ER. Decide whether each statement is true or false, and explain why. A. The signal peptide binds to a hydrophobic site on the ribosome causing a pause in protein synthesis, which resumes when SRP binds to the signal peptide. B. Nascent polypeptide chains are transferred across the ER membrane through a pore in the protein translocator complex. C. In multipass transmembrane proteins, the odd-numbered transmembrane segments (counting from the N-terminus) act as start-transfer signals, while the even-numbered segments act as stop-transfer signals. D. The ER lumen contains a mixture of thiol-containing reducing agents that prevent the formation of S-S linkages (disulfide bonds) by maintaining the cysteine side chains of luminal proteins in reduces (-SH) form.