Ans.
During protein synthesis, RNA is transcribed by RNA polymerase using information present in template DNA strand. The newly formed RNA is known as primary transcript or hnRNA (hetero-nuclear RNA), which represents an unprocessed RNA. It contains both coding (exons) and non-coding (introns) sequences.
Introns are removed from hnRNA as they do not code for any enzyme or functional product and resulting RNA is known as mature RNA.
Thus, the correct answer is option). 'introns.'
