Which оf the fоllоwing stаtements аre TRUE regаrding chlamydia infection? I. Chlamydia infection is caused by Chlamydia genitalis. II. Chlamydia is the most commonly reported parasitic sexual transmitted infection in the United States. III. A large number of chlamydia cases are not reported because infected individuals are asymptomatic and do not seek testing or treatment. IV. In pregnant women, untreated chlamydia infection has been associated with pre-term delivery.