What are the steps on solving this problem?

22.2 The figure shows a pendulum consisting of a mass m=2kg connected to a massless string of length L=0.5 m. The string is pulled back to an angle , and released from rest. If the tension in the string is T=30N when the mass returns to the vertical position what is the initial angle do? (A) 50.10 (B) 42.70 (C) 16.20 (D) 35.3 (E) 23.50