Barnase, barstar and bar genes are used for developing genetically modified

Answer: Option B

Barnase, barstar and bar genes are used for developing genetically modified Mustard.
Barnase-barstar gene system was used to develop a line of non-self-fertilizing transgenic mustard (Brassica juncea) plants with enhanced outbreeding capability.
The barnase-barstar transgene-based hybrid seed production technology has been commercially deployed in crops like Brassica napus.
The system utilizes the expression of the barnase gene, encoding cytotoxic RNase protein in the tapetum cells to make one of the combiner's males sterile.