Final answer:
Code-switching refers to altering or changing one's speaking approach for environmental adaptation and it is a sign of communicative competence. It is commonly used by individuals who are multilingual or who speak different dialects, allowing them to navigate various social and professional contexts effectively. This practice is widespread in areas with diverse linguistic backgrounds, including postcolonial regions.
Step-by-step explanation:
Code-switching is the practice of moving back and forth between different linguistic styles or languages in different contexts or with different interlocutors. The correct answer to the question "Code-switching refers to:" is b) Altering or changing speaking approach for environmental adaptation. Code-switching is a sign of communicative competence, not incompetence, and it's not a language disorder nor is it limited to non-verbal communication techniques.
It often occurs in environments where speakers share more than one language in common, or it can involve shifting between dialects within a single language. For instance, in areas that were previously colonized by Europeans, local populations might switch between their local languages and the European language that has been maintained as the formal language of government and education.
Particularly for speakers of 'nonstandard' dialects or vernaculars, code-switching can be a way to navigate social structures that privilege certain languages or forms of speaking in public spheres. Individuals may code-switch to convey a certain identity or to be better understood by their audience.
Such communication strategies are useful in a wide range of contexts, from casual conversations to the highest levels of political speech as demonstrated by public figures like U.S. President Barack Obama. Moreover, this linguistic flexibility can be seen as a form of resistance against linguistic marginalization, celebrating the 'home' languages and enhancing communication within diverse communities.