(i) All reproductive tract infections, (RTIs) such as syphilis, gonorrhoea, genital herpes, etc. are transmitted through sexual intercourse with an infected person; hence they are all STDs. 
(ii)  But there are diseases like AIDS, hepatitis B, etc. which are also transmitted through sexual intercourse, i.e. they are STDs, but they do not specifically affects the reproductive organs; hence they are not RTIs.

It signifies that it is the case of male infertility, where the sperm count is low. That's why the couple has been advised to undergo artificial insemination.

Surrogacy is a practice in which a woman ( a surrogate mother ) bears a child for a couple unable to produce children; usually, because the wife is infertile or unable to carry a pregnancy to full term.
The surrogate mother is impregnated with the use of artificial insemination or through the implantation of the embryo produced by in vitro fertilization.

AIDS is a fluid transmitted disease and is considered as an STD because the probability of fluid transmission is maximum during sexual intercourse.

Oral contraceptive or pills are either progestogens or progestogen-oestrogen combinations.
They function as contraceptives by
(i) inhibiting ovulation
(ii) inhibiting implantration.
(iii) altering the quality of cervical mucus to prevent or stop the entry of sperm.