Lets first find the total # of ways they can be arranged without restrictions
6P6=6!=720.......(1)

Now, lets find the # of ways that Ann and Bea will always be together

Ann Bea Cam Don Ella Fey

Lets replace Ann and Bea with an X

X Cam Don Ella Fey can be arranged amongst themselves in 5P5 ways=5!=120....(a)
But, inside of X, Ann and Bea can be arranged in 2 ways ie. Ann Bea or Bea Ann...So 2 ways.

Total # of ways in which Ann and Bea will always be together is 120*2=240 ...(2)

Total # of ways they can be arranged with no restrictions-Total # of ways in which Ann and Bea will always be together=Total # of ways where Ann and Bea will never be together.

Total # of ways where Ann and Bea will never be together=720-240=480 hence C