Match the following techniques or instruments with their usage:

(a)	Bioreactor	(i)	Separation of DNA fragments
(b)	Electrophoresis	(ii)	Production of large quantities of products
(c)	$\mathrm{PCR}$	(iii)	Detection of pathogen, based on antigen-antibody reaction
(d)	$\mathrm{ELISA}$	(iv)	Amplification of nucleic acids

Select the correct option from following:

• A

  $\left(\mathrm{a}\right)-\left(\mathrm{iii}\right), \left(\mathrm{b}\right)-\left(\mathrm{ii}\right), \left(\mathrm{c}\right)-\left(\mathrm{iv}\right), \left(\mathrm{d}\right)-\left(\mathrm{i}\right)$
• Correct answer
  B

  $\left(\mathrm{a}\right)-\left(\mathrm{ii}\right), \left(\mathrm{b}\right)-\left(\mathrm{i}\right), \left(\mathrm{c}\right)-\left(\mathrm{iv}\right), \left(\mathrm{d}\right)-\left(\mathrm{iii}\right)$
• C

  $\left(\mathrm{a}\right)-\left(\mathrm{iv}\right), \left(\mathrm{b}\right)-\left(\mathrm{iii}\right), \left(\mathrm{c}\right)-\left(\mathrm{ii}\right), \left(\mathrm{d}\right)-\left(\mathrm{i}\right)$
• D

  $\left(\mathrm{a}\right)-\left(\mathrm{ii}\right), \left(\mathrm{b}\right)-\left(\mathrm{i}\right), \left(\mathrm{c}\right)-\left(\mathrm{iii}\right), \left(\mathrm{d}\right)-\left(\mathrm{iv}\right)$

Hence, the correct answer is option: 'B'.