Which of the following principle will not help people to become free from the infection of sexually transmitted diseases?

i) Aways use condoms in the course of coitus.

ii) Avoid sex with unknow partners/multiple partners

iii) Refer any one in case of doubt for early detection and diagnose of disease and get complete treatment.

iv) In case of doubt, go to a qualified doctor for early detection and get complete treatment if diagnosed with disease.

v) Involovement in sex with known partners/single prtners