Question

I need it's answer urgently ​

Answer 1

I guess you're asking for the (b) one so here:

1- Always use condoms

2- Preferably have only one sexual partner (your spouse)

3- Check regularly for infections, to prevent catching a STD

Answer 2

Safe sexual behavior :

Safe sex is sexual activity using methods or devices (such as condoms) to reduce the risk of transmitting or acquiring sexually transmitted infections (STIs), especially HIV.[1] "Safe sex" is also sometimes referred to as safer sex or protected sex to indicate that some safe sex practices do not completely eliminate STI risks. It is also sometimes used to describe methods aimed at preventing pregnancy.

Three safe sexual behavior are:

a) Masturbation

b) Abstinence

c) Use of condom