STD 12 - 2. human reproduction — NEET STD 11 Science — Question

$I.$ $PCT$ $II.$ $DCT$

$III.$ Loop of Henle $IV.$ Collecting duct

Which contributes most in maintaining $pH$ of blood?

$(1)$ Medical termination of pregency $(MTP)$ during first trimester is generally safe

$(2)$ Generally chances of conception are nil until mother breast-feeds the infant upto two years

$(3)$ Intrauterine devices like copper$-T$ are effective contraceptives

$(4)$ Contraception pills may be taken upto one week after coitus to prevent conception Which two of the above statements are correct?