The correct option is B Split gene
Split gene is an interrupted gene having exons and introns. The exons are expressed as RNA and protein while the introns are not expressed. The operator gene is a regulatory gene which provides binding site for a transcription factor to regulate gene expression. Genes that are synthesized artificially in the laboratory are called as synthetic genes. The genes which are expressed in presence of a modifier gene, are called as epistatic gene. Correct option is A.