By which method was a new breed ‘Hisardale’ of sheep formed by using Bikaneri ewes and Marino rams?

The correct option is B Cross breeding
Cross breeding is the process where the breeding between the two individuals of different species takes place resulting in the production of hybrid progeny. “Hisardale" is a new breed of sheep developed by cross breeding between Bikaneri ewes and Marino rams in Punjab.

Inbreeding refers to the mating of more closely related individuals within the same breed for 4-6 generations.

Out crossing is the practice of mating of animals within the same breed, but having no common ancestors.

Mutation breeding is the process of breeding through mutation with the desirable traits.