Which among the following is not a preventive measure against STIs?

The correct answer is Option (4) → None of these.

Sexually transmitted infections (STIs) are infections passed on through sexual intercourse. NCERT gives three simple principles that keep a person free of them, and options (1), (2) and (3) are these same three. Since every option given is a preventive measure, none of them can be the one that is “not” a preventive measure.

Option (1) Avoid sex with unknown partners/multiple partners. — A preventive measure. Sex with unknown or multiple partners raises the chance of meeting an infected person, so avoiding it is the first principle.

Option (2) Always try to use condoms during coitus. — A preventive measure. A condom works as a barrier during coitus, so it also protects the user from contracting STIs and AIDS.

Option (3) One should go to a qualified doctor for early detection and get complete treatment if diagnosed with infection. — A preventive measure. Early symptoms are often minor and infected females may show none. Going to a qualified doctor when in doubt allows early detection and complete treatment.

NCERT Extract:
Sexually Transmitted Infections (STIs) – “… There is no reason to panic because prevention is possible. One could be free of these infections by following the simple principles given below: (i) Avoid sex with unknown partners/multiple partners. (ii) Always try to use condoms during coitus. (iii) In case of doubt, one should go to a qualified doctor for early detection and get complete treatment if diagnosed with infection.”