This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
A 21 year old female presented with mucopurulent discharge from eyes and foreign body sensation diagnosed of having inclusion conjunctivitis. It is caused by: 
Select and explain. 
A. Chlamydia trachomatis, B. Chlamydia psittaci, C. Herpes, D. Gonorrhoea
A: Chlamydia trachomatis
Answer: A: Chlamydia trachomatis 
Explanation: Inclusion conjunctivitis is caused by Chlamydia trachomatis serovars D-K. The primary source of infection is urethritis in males and cervicitis in females. The transmission of infection may occur to eyes either through contaminated fingers or more commonly through water of swimming pools (hence the name swimming pool conjunctivitis). Ref: Comprehensive Ophthalmology by AK Khurana, 4th edition, Page 68.