The answer is $($A$)$

A simple pendulum made of a string of length $L$ tied to a ball with mass $m$ swings so that at its lowest point, the speed of the ball is $v_b$; the pendulum makes a maximum angle ${}_m$ with the vertical. What is the tension in the string when it is at the an angle $<msub><mrow><mi></mi></mrow><mrow><mi>m</mi></mrow></msub>$ with the vertical?

A$)mg(3cos-2cos{}_m)$

B$)mg(2cos{}_m+3cos)$

C$)$ mgcos$$

D$)mg(2cos{}_m-3cos)$

E$)mg(2-cos)$