I think answer is wrong, below example by calculation. Anyone, pls verify. Thanks.
In equilibrium: Anti-clockwise torque by W = Clockwise torque by Spring
at mid point: Fw (N) x 0.5 (m) = Fs (N) x 0.5 (m)
as W moves to pivot, e.g.: same Fw (N) x 0.2 (m) = Fs’ (N) x 0.5 (m) ->lower torque on both sides
So Fs’ should be lower (Decreased downward force of spring acting on the ruler) – Answer (B)