Under What Conditions Can AP Reporters Use Anonymous Sources

Under what conditions can AP reporters use anonymous sources?

A) When the material is opinion or speculation; when information is not available anywhere else; and when the source is reliable
B) When the material is information and vital to the report; when information is not available anywhere else; and when the source is nameless
C) When the material is information, not opinion, and is vital to the report; when information is only available under the conditions of anonymity; and when the source is reliable
D) When the material is information and vital to the report; when the information is also available on the Internet; and when the source is reliable