Match the following columns and select the correct option.

Column-$I$	Column-$II$
$(a)$ $Bt$ cotton	$(i)$ Gene therapy
$(b)$ Adenosine deaminase deficiency	$(ii)$ Cellular defence
$(c)$ $RNAi$	$(iii)$ Detection of $HIV$ infection
$(d)$ $PCR$	$(iv)$ Bacillus thuringiensis

• A
  $(i), (ii), (iii), (iv)$
• B
  $(iv), (i), (ii), (iii)$
• C
  $(iii), (ii), (i), (iv)$
• D
  $(ii), (iii), (iv), (i)$