The correct answer is option 4 - Eye. Trachoma is an infectious disease that affects the eyes. It is caused by the bacterium Chlamydia trachomatis. Trachoma is a leading cause of preventable blindness worldwide, particularly in developing countries with poor sanitation and limited access to healthcare. The bacteria is spread through direct contact with the discharge from the eyes or nose of an infected person. Trachoma can cause inflammation and scarring of the inner surface of the eyelids, which can lead to the eyelashes turning inwards and scratching the cornea. If left untreated, repeated infections can result in irreversible vision loss. Trachoma is a major public health concern and efforts are underway to eliminate the disease globally.