Two bars each of mass $m$, but one having a length $l$ and the other $2l$ are released from rest as shown. The pin reaction at $A$ at the instant the bar is released for the two setups ($a$) and ($b$) shown are related as _______.

A. $R_a = R_b$
B. $R_a = 0.5R_b$
C. $R_a = 2R_b$
D. None of the above