i wonder how to solve this question

4. Let X1, ..., Xn be a random sample from N(u, 1). Define Ti = (X,) and T2 = {n(n - 1)}-Exitin XiX; as two estimators of ?, where Xn = n- EXi. (a) Show that both Ti and T2 are consistent for 2. (b) Find the asymptotic distributions of Ti. (c) (Optional) Find the asymptotic distributions of T2