The correct option is B Introns
Recon
Recon is the unit of recombination present on the DNA.
Muton
Muton is the element of the DNA that is capable of undergoing mutation easily.
Exons
Exons are the coding sequences of a cistron (the entire DNA segment that codes for a polypeptide). During transcription, exons are transcribed into the RNA transcript.
Introns
Introns are non-coding sequences which are also transcribed into the primary RNA transcript or hnRNA. However, before transporting the hnRNA to the cytoplasm, the introns are eliminated and exons are joined by the process of splicing.
Final answer
(D) Introns