- A Gonorrhoea
- B Chlamydia
- C Trichomoniasis
- D Syphilis
Correct answer: C. Trichomoniasis
Explanation: Trichomoniasis is caused by Trichomonas vaginalis, a flagellated protozoan. It is the most common curable STI worldwide.
Concept context
Understand reproductive health, family planning, contraception methods, STIs, population control, and assisted reproductive technologies.