Protein X Contains Four Transmembrane Domains,a Short N-Terminus and a Long

Multiple Choice

Protein X contains four transmembrane domains,a short N-terminus and a long C-terminus.Following protein synthesis,the N-terminus of the protein faces the lumen (the inside) of the ER.After protein X is transported to the cell surface via exocytosis,you would expect the N-terminus of protein X to be

A) extracellular.
B) cytoplasmic.
C) in the lumen.
D) in the lipid bilayer of the plasma membrane.