. Earliest symptom of carcinoma cervix is:
Thus earliest symptom is irregular vaginal bleeding which usually follows coitus. So I am taking option ‘a’, i.e. irregular vaginal bleeding as the correct answer.
Also Know: 
• CIN is most commonly detected in women in their 20’s.
• Peak incidence of carcinoma in situ: 25 - 35 years
• Ca cervix has bimodal peak - first at 35-39 years and second at 60-64 years.
Irregular vaginal bleeding
Post coital bleed
Foul smelling discharge
Pain