"A character sketch is a description made for the purpose of guiding the writer on such assignments as introducing a particular character to the reader in such a way that both the writer and readers can have a quick overview of the character's attributes; including but not limited to physical appearance, idiosyncratic (individual) tendencies in different circumstances, state of mind as shaped by former experiences and how these will affect their future actions."
Option D: There are various aspects to a character. History is just a part of it. Though it's important, it must not be lengthy. The character sketch is not just the history of the character. Hence option D is correct.
Option A: The history shouldn't be lengthy because then the reader would get lost in the middle of the sketch. It should be brief since the sketch is not just the history.
Option B: The history is not as important as the character. It's one aspect of the character. The others include the character's personality, likes, dislikes, hobbies, appearances, style, clothes and so on.
Option C: It is not essential to include the major events of the character's life. If they are not relevant to the story, then they wouldn't be included. Extra information would not help the story.
Hence options A, B and C are wrong.