Concept:Language acquisition is the natural, subconscious process of picking up a language through exposure, without formal instruction or conscious effort.Explanation:Language acquisition happens naturally when children hear and interact with their environment. They learn by listening and imitating. No deliberate study or formal teaching is needed. This is how a child learns their first language. It is different from language learning, which involves conscious study of grammar and rules. In the options, option A correctly describes this process—learning without deliberate or conscious effort. Option B is language learning through a method. Option C refers to using the mother tongue, which is not necessary for acquisition. Option D describes conscious learning, not acquisition. Therefore, only option A matches the definition.Answer:A. learning a language without making any deliberate or conscious effort.