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

None of these.

The correct answer is Option (4) -None of these

All the options provided are preventive measures against sexually transmitted infections (STIs).

Infections or diseases which are transmitted through sexual intercourse are collectively called sexually transmitted infections (STI) or venereal diseases (VD) or reproductive tract infections (RTI). Gonorrhoea, syphilis, genital herpes, chlamydiasis, genital warts, trichomoniasis, hepatitis-B and HIV leading to AIDS are some of the common STIs.

The preventive measure from the STIs are :
(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.