Big Brother and the Bully

So, you're sitting on a swing on the playground, just going back and forth, back and forth, and some kid bigger than you comes up behind and shoves you into the dirt.
You have as much right to swing as he does, but you know if you make an issue of it, he's gonna pound your ass.
So you do the responsible thing. You tell your big brother in Junior High to stand for your rights.
Said big brother waits for this obvious thug after school, and calls him on his antisocial tendencies.
Of course, the bully says he didn't do it, and BB has no proof, just what his little brother told him.
So BB tells him, if he hears about it again, he's gonna kick bully's ass. This is a red line he'd better not cross.

So Bully, being a bully, lays off LB in order to avoid a butt-whoopin'. This is good. This works.
But now LB sees that Bully has been put in his place, and knows he can't touch him, so he taunts and teases Bully until, finally, after some particularly rude remarks about his ancestry, Bully has enough, and shoves little brother in the dirt face first.

Big Brother, being advised by Little Brother that Bully was picking on him again, once more waits and accosts the bully.
Does he:
A. Threaten to beat him up again?
B. Beat him up on his little brothers word (and probably get expelled from school for it...)?
C. Give the bully a chance to state his side of the story?
D. Have LB and Bully fight it out while he stands by to make sure neither side uses chemical weapons of mass destruction?
or
E. Congratulate the bully on not taking any shit?

And, an extra credit question: Which answer would Obama choose?

Lets hear some opinions on this in the comments. Just for historical purposes of course.