Syphilis is an infectious bacterial disease caused by Treponema pallidum with $3$ stages

$(A)$ Infectious painless ulcers on the genitals $\quad$$(i)$ First

$(B)$ Blindness, heart trouble,aortic impairment $\quad$$(ii)$ Second

$(C)$ Skin lesions, hairloss,swollen joints $\quad$$(iii)$ Third
Which of the following is the correct match between the symptoms and stage?

World Population Day is

Population density of India is

Cause of decline of population in $1927$ was