Consider the sequence of events that direct a secretory protein into the endoplasmic reticulum. In the following list, which of the following is the last event in this sequence of reactions?
a) Binding of the signal recognition particle (SRP) to the signal sequence of the protein.
b) Translocation of the ribosome-bound nascent protein to the ER membrane.
c) Recognition and binding of the SRP receptor on the ER membrane.
d) Translation of the protein into the ER lumen.
