Right answer is (a) True
Easiest explanation: Using suppressed weir formula the discharge through the opening is given when discharge consists of flow over upper part of section (HL may be considered as free discharge), then the discharge is given by q1 = (2/3) x Cd1 x \(\sqrt{2g}\) x B x HL^3/2 and if the flow is through the remaining part (through submerged orifice) the discharge is given by q2 = Cd2 x \(\sqrt{2gH_L}\) x B x d.
Total discharge is given by q = q1 + q2.