One who changes because of events in the plot and is multi-dimensional.
a. flat character
b. major character
c. round character
d. minor character

Sounds like a round character, flat characters and minor characters don't do this.

I believe that the answer would be b) Major Character, as these characters tend to progress with the plot. Some examples include Frodo in The Lord Of The Rings or Anakin in Star Wars.

just say it's your friend did it and you had no idea?

answer:

a. "there, said he, there is something for you."

explanation:

"said he" should not have been part of what is in the dialogue.