During a casual conversation with a colleague, you mention an idea that you're going to pitch to your boss. Later that day, your colleague discusses the same idea with your boss and claims it as his own. You:
A.) Rush into your boss's office and tell her your colleague is a "LIAR!"
B.) Wait until you're composed to approach your boss. Let her know the idea was yours and you worked long and hard on it. As for your colleague, you'll think twice about confiding in him from now on.
C.) You're angry, but if your co-worker takes the credit there's really not that much you can do about it.