Carrier pigeons
(which of the following statements from the passage supports the author's conclusion that carrier pigeons sometimes had a dangerous job?

a. in 1815 an english banker named nathan rothschild made his fortune by replying on messages sent to him by carrier pigeons.

b. since they could easily be realesed from airplanes or ships, every branch of the armed services used the birds.

c. on his last mission, though wounded, he carried a message that saved the lives of 194 american soilders.

d. many people finds carrier pigeons ugly because of their big wattle, a knobby buildup of skin on the beak.