I wonder how to solve this question

Let X1, ..., Xn be a random sample from N(u, 1). Define Ti = (Xn) and T2 = {n(n - 1)}-Exitin XiX; as two estimators of , where Xn = n- EXi. (a) Show that both Ti and To are consistent for u2. (b) Find the asymptotic distributions of T1. (c) (Optional) Find the asymptotic distributions of T2