Final answer:
Discourse in linguistics is C) a spoken or written communication that also encompasses non-verbal elements and cultural practices within different social contexts.
Step-by-step explanation:
In linguistics, a discourse refers to C) a spoken or written communication, which includes not only verbal exchanges but also written texts and other forms of communication within a social context.
This can also encompass the broader set of interactions that establish the norms, rules, and cultural practices within speech communities.
Discourse allows us to understand how language functions within various domains of social life, such as academic environments, where we enter and adapt to the academic discourse community, or different regions, where variations in dialect might lead to distinct local forms of discourse.
It's worth noting that the concept of a discourse extends beyond mere words to include non-verbal elements that are critical to communication, such as tone and body language, integrating into the more extensive sociolinguistic and anthropological frameworks that seek to understand language as an intricate part of human culture and social interaction.