Which sentence uses dashes correctly?


I am so mad at you for spilling soda--on my homework--that could oh, just forget it.


I am so mad at you for spilling soda on my homework--that could oh, just forget it.


I am so mad at you for spilling soda on my homework that could --oh, just forget it.


I am so mad at you--for spilling soda on my homework--that could oh, just forget it.