In Which of the Following Circumstances Would a Defendant to a Claim

In which of the following circumstances would a defendant to a claim for monies due and owing in the small claims court, be advised to a file a defence to the claim?

A) the plaintiff is claiming interest
B) the defendant admits to owing the debt
C) the defendant wishes to have a structured settlement arrangement with the plaintiff
D) the defendant denies owing the debt or denies owing the entire sum claimed
E) the defendant requires time to pay the debt