46.Which of the following statement about the physical layer protocol is true? a.The physical layer provides the mechanism for opening, closing and managing a session between end-user application...

46.Which of the following statement about the physical layer protocol is true?
a.The physical layer provides the mechanism for opening, closing and managing a session between end-user application processes.
b.The physical layer changes the value of a bit being transmitted due to electromagnetic interference
c.The physical layer specifies the shared protocols and interface methods used by hosts in a communication network
d. The physical layer uses the port number to deliver traffic.