Sarah and William Got into an Argument

Multiple Choice

Sarah and William got into an argument.The next day,Sarah reflects on why they behaved the way they did.According to the actor-observer difference,Sarah should think,

A) "I wonder what I did to make William so angry."
B) "I happened to have a bad day, but William is just plain nasty."
C) "William must have had a bad day, but I am just plain nasty."
D) "I wonder what William did to make me so angry."