Consider the following $4-$message protocol:

$1.$ A$->$S: $($B$,\{($A$,$ K$1)\}$KpbS$)$

$2.$ S$->$B: A

$3.$ B$->$S: $($A$,\{($B$,$ K$2)\}$KpbS$)$

$4.$ S$->$A: $($B$,\{$K$2\}$K$1)$

Which one of the following statements is true, at the end of the protocol, and with regards to the purpose of the protocol:

a$)$ Both A and B establish a session key K$2,$ and B is sure of A$$s identity

b$)$ Both A and B establish a session key K$1,$ and B is sure of A$$s identity

c$)$ Both A and B establish a session key K$1,$ and A is sure of B$$s identity

d$)$ Both A and B establish a session key K$1,$ and both B and A are sure of each other$$s identity

e$)$ Both A and B establish a session key K$2,$ and A is sure of B$$s identity

f$)$ Both A and B establish a session key K$1$

g$)$ Both A and B establish a session key K$2$

h$)$ Both A and B authenticate each other by knowing each other$$s identities

i$)$ A ends up knowing B$$s identity

j$)$ B ends up knowing A$$s identity

k$)$ None of the above

l$)$ All of the above