Which part of speech is the underlined word in the following sentence? The kind of language learnt in each setting differs too.

The word 'each' in this sentence functions as a determiner because it specifies or determines the noun 'setting' that follows it. Determiners include words like 'each', 'every', 'this', 'that', 'some', 'any', etc. It is not a pronoun (which would replace a noun), nor a conjunction or preposition. Hence option (2), Determiner, is correct.