If end to end connection is done at a network or IP level, and if there are N hosts, then what is the number of keys required?

If end to end connection is done at a network or IP level, and if ther

1.	If end to end connection is done at a network or IP level, and if there are N hosts, then what is the number of keys required?
A.	N(N-1)/2
B.	N
C.	N(N+1)/2
D.	N/2
Answer» B. N