Final answer:
Language diffusion occurs when a language area expands or relocates in a geographic area. It can happen through migration, colonization, and cultural contact and borrowing.
Step-by-step explanation:
The correct answer is a) Diffusion. Language diffusion occurs when a language area expands or relocates over time in a geographic area where it is spoken. This can happen through the movement and interaction of people, such as migration or colonization. It can also occur through cultural contact and borrowing, where people adopt and incorporate elements of another language into their own.
the principal method of human communication, consisting of words used in a structured and conventional way and conveyed by speech, writing, or gesture:
"a study of the way children learn language"
a system of communication used by a particular country or community:
"the book was translated into twenty-five languages"