Which of the following present similar to unruptured ectopic pregnancy: (A) Follicular cyst of ovary, (B) Corpus luteum cyst, (C) Polycystic ovary disease, (D) Ovarian torsion
Answer is B. Halban's classical traid:

Delay in normal period followed by spotting
Unilateral pelvic pain 
Small Tender adnexal mass.

This triad is similar to that seen in classic ectopic pregnancy.