In which of the following method of animal breeding is two different species of male and female animals allowed to mate?

The correct option is A Interspecific hybridisation
Outbreeding refers to the cross between differently related individuals those of same or different species. These can be of the following types:-

• Outcrossing refers to mating between individuals of same breed with no common ancestors for the past 4 to 5 generations.
• Crossbreeding refers to process in which superior individuals of both sexes from two different breeds are allowed to mate.
• Interspecific hybridisation is the practice of animal breeding in which male of one species is mated with the female of another species. For example, mule is the result of cross between female horse and male donkey.

Inbreeding refers to mating of closely related individuals of the same breed over few generations.

Hence, the correct option is b.