Puzzling Plural/Pluraling Puzzle

A stray thought:

• Question: What is the correct plural of Attorney-General? Is it (a) Attorney-Generals? Or (b) Attorneys-General? Or even (c) Attorneys-Generals?
• Answer: I genuinely don't know and haven't looked it up (not yet anyway). Option (a) sounds most right to me, but I've heard (b) used on occasion. I threw in (c) just for the heck of it.