Consider the statements given below regarding contraception and answer as directed thereafter:
(i) Medical Termination of Pregnancy (MTP) during first trimester is generally safe
(ii) Generally chances of conception are nil until mother breast-feeds the infant upto two years
(iii) Intrauterine devices like copper-T are effective contraceptives
(iv) Contraception pills may be taken upto one week after coitus to prevent conception
Which two of the above statement are correct?

Given below are four methods (A-D) and their modes of action (1-4) in achieving contraception. Select their correct matching from the four options that follow:

Method	Mode of Action
(1) The pill	(a) Prevents sperms reaching cervix
(2) Condom	(b) Prevents implantation
(3) Vasectomy	(c) Prevents ovaulation
(4) Coppe	(d) Semen contains no sperms

The formula for exponential population growth is-

Test tube baby means a baby born when