30.Which of the following is correct with regard to learners’ errors as sources of insight into the learning processes? (A) Learners’ errors provide evidence of the system of language at any particular point in the course of L2 development. (B) Learners’ errors provide evidence of the strategies or procedures in their discovery of the language. (C) Learners’ errors provide evidence of testing their hypothesis about the nature of the language. (D) All of the above.