A message can be sent from one transmitter to another among 9 transmitters A,B,C,D,E,F,G,H and , as shown below.
From A to B, from B to C, from C to D, from B to E, from D to H, from E to F, from E to H, from G to H, from F to G, from H to I, from G to I and from D to I.
In how many ways can a message be sent from A to I?

A:7
B:6
C:5
D:4
Answer: C