The correct option is A Pusa swarnim
Pusa swarnim is a variety of mustard that is resistant to white rust caused by fungi.
Pusa sawani is a variety of okra that is resistant to shoot and fruit borer insects. Pusa sem 2 is a variety of flat bean and is resistant to jassids, aphids and fruit borers. Pusa gaurav is a mustard variety that is resistant to aphids.
So, only Pusa swarnim is resistance to a disease, whereas the rest of the options are resistant to various insects.