Amniocentesis can be used to test a foetus for the presence of which…

The correct answer is Option (1) → A, B and C only

In amniocentesis, some amniotic fluid around the developing foetus is taken out, and the foetal cells and dissolved substances in it are studied. The cells carry the foetus's own chromosomes and genes, so the test can show genetic disorders. It cannot show infections that a person catches after birth.

(A) Down syndrome — Tested by amniocentesis. It is a chromosomal disorder caused by an extra copy of chromosome 21, which can be seen in the foetal cells.

(B) Haemophilia — Tested by amniocentesis. It is a sex-linked recessive disorder in which a blood-clotting protein is affected.

(C) Sickle-cell anaemia — Tested by amniocentesis. It is an autosomal recessive disorder in which the β-globin chain of haemoglobin is changed.

(D) Typhoid — Not tested by amniocentesis. Typhoid is an infectious disease caused by the bacterium Salmonella typhi, taken in through contaminated food and water. It is not a genetic disorder of the foetus.

The book spells the disorders “down syndrome” and “sickle-cell anemia”; these are the same Down syndrome and sickle-cell anaemia named in the question.

NCERT Extract:
Reproductive Health – Problems and Strategies – “… In aminocentesis some of the amniotic fluid of the developing foetus is taken to analyse the fetal cells and dissolved substances. This procedure is used to test for the presence of certain genetic disorders such as, down syndrome, haemoplilia, sickle-cell anemia, etc., determine the survivability of the foetus.”
Common Diseases in Humans – “… Salmonella typhi is a pathogenic bacterium which causes typhoid fever in human beings. These pathogens generally enter the small intestine through food and water contaminated with them and migrate to other organs through blood.”