Step 1: Understanding amplification of nucleic acid.
Amplification means producing multiple copies of a specific DNA sequence. The most widely used method for this is Polymerase Chain Reaction (PCR).
Step 2: Analyzing the options.
(A) Transformation: Incorrect — It introduces foreign DNA into a host, not amplification.
(B) Transfection: Incorrect — This refers to introducing nucleic acids into eukaryotic cells, not amplification.
(C) PCR: Correct — PCR is the standard technique for amplifying DNA in vitro, producing millions of copies.
(D) Micropropagation: Incorrect — It is a plant tissue culture technique, unrelated to nucleic acid amplification.
Step 3: Conclusion.
The correct method for amplification of nucleic acid is PCR.