Concept:A speech community is defined by shared linguistic norms and expectations, not by geography or purpose.
Explanation:In sociolinguistics, a speech community refers to a group of people who follow common rules for using language.
These rules include how words are pronounced, which words are appropriate, and how sentences are formed.
The key idea is that members of a speech community share the same norms about language use, even if they live in different places.
Option A is incorrect because speaking a specific variety for a purpose does not define a community.
Option C is wrong because a speech disorder is unrelated to community norms.
Option D is incorrect because teaching a language does not imply shared norms among the group.
Only option B matches the sociolinguistic definition: shared norms regarding language use.
Answer:Option B: who share the same norms regarding the use of languages