Step 1: Understanding the Question.
When a suit is filed against multiple parties and an ex parte decree is passed, those who did not appear can apply to set the decree aside. Here, A and B, who did not appear, can apply to set the ex parte decree aside.
Step 2: Analysis of Options.
- (A) Only C: This is incorrect, as C was served the summons and cannot apply to set the decree aside.
- (B) Only A & B: This is the correct answer, as A and B did not appear and can apply to set the ex parte decree aside.
- (C) A, B and C: This is incorrect because C is already part of the decree and cannot apply to set it aside.
- (D) None of these: This is incorrect as option (B) is the correct answer.
Step 3: Conclusion.
Thus, the correct answer is (B) Only A & B.