Language with a relatively sophisticated and explicit expression of meaning and motivation is known as:

The correct answer is B: Elaborated codes.

In Basil Bernstein's theory of linguistic codes, elaborated codes are characterized by a sophisticated and explicit expression of meaning and motivation. This form of language is context-independent, meaning it can convey clear and detailed information to listeners who do not share the speaker's background or assumptions. It typically involves a wider vocabulary, more complex grammatical structures, and a greater use of adjectives, adverbs, and logical connectives, allowing for nuanced and precise communication of abstract ideas and individual perspectives.

• Option A: Restricted codes is incorrect. Restricted codes are context-dependent, implicit, and often rely on shared understanding among speakers. They tend to have simpler grammatical structures and a more limited vocabulary, focusing on concrete, immediate situations rather than explicit explanations of motivation or abstract concepts.
• Option C: Communication codes is incorrect. This is a broad, generic term for any system of communication. It is not a specific concept within sociolinguistics that describes language with sophisticated and explicit expression of meaning and motivation.
• Option D: None of these is incorrect because 'Elaborated codes' precisely fits the description.