During the Years 2011 to 2016, in a Particular District

During the years 2011 to 2016, in a particular district, 1,000 of 10,000 girls aged 16 to 18 years tested positive for a sexually transmitted infection (STI) . Of the 1,000 diagnosed STIs, 300 were gonorrhea and 500 were chlamydia. Which statement would the CHN recognize as being true?

A) The proportion of cases of gonorrhea to all STIs was 300:1,300.
B) The proportion of cases of gonorrhea to chlamydia was 300:500.
C) The proportion of STIs to the total population was 10 per 1,000.
D) The proportion of cases of gonorrhea to all STIs was 50%.