Let’s see, who is smart?
who can answer the question in 2

which one is correct?

select one:
a. when we decapsulate packets we remove data link layer header
b. when we decapsulate frames we remove transport layer header
c. when we encapsulate frames we add network layer header to the frame
d. when we encapsulate message we add transport layer header
e. when we encapsulate segments we add application layer header