Match column - I with column - II. 

	Column - I		Column - II
A)	Gene therapy	I)	Separation of DNA fragments
B)	RNA interference	II)	Diagnostic test for AIDS
C)	ELISA	III)	Cellular defence
D)	Gel Electrophoresis	IV)	Allows correction of a gene defect

Choose the correct answer from the options given below. 

	A	B	C	D
(1)	IV	I	II	III
(2)	IV	II	III	I
(3)	IV	III	II	I
(4)	IV	III	I	II

A-IV, B-III, C-II, D-I
A. Gene therapy allows correction of a gene defect. Gene therapy involves the introduction of healthy genes into cells to replace or correct faulty genes, aiming to treat genetic disorders.
B. RNA interference (RNAi) is a cellular defence mechanism that regulates gene expression and defends against foreign genetic material, such as viruses and transposons. It involves the silencing or down regulation of specific genes through the action of small RNA molecules.
C. Enzyme-linked immunosorbent assay (ELISA) is a widely used screening test for AIDS. It detects HIV antibodies.
D. Gel electrophoresis is a technique used to separate and analyze DNA fragments based on their size.