What is the difference between Option A and C? I've been told that finding people is hard if you're not paying anybody. And if you do find people to work with you for free, they may or may not stick around.
Option A, you have a say in the game. It's an equal partnership.
Option C, you simply give them the story to include in the game and have no say in the game otherwise.
Yes, under Option A the person may lose interest. Under Option C they might never make the game. There's always a risk when you work with other people. But sometimes games do get made.