Answer:
colonization
Step-by-step explanation:
Language diffusion can be defined as the move of language from its origin to other places.
The British colonized Australia in 1788 after claiming the land as British territory in 1770. A new government was formed to oversee the affairs of the country and as a result of this colonisation, the Australians had to learn English language because that was what their colonial masters spoke and used to communicate.
Therefore, the correct answer is B