Consider the following statements regarding corona:

1. It causes radio interference.
2. It attenuates lightning surges.
3. It causes power loss.
4. It is more prevalent in the middle conductor of a transmission line employing a flat conductor configuration.

Which of the above statements are correct?

A. 1, 2 and 3 only
B. 1, 2 and 4 only
C. 1, 2, 3 and 4
D. 3 and 4 only