In a T-beam, the vertical distance between the bottom of the flange and the centre of the tensile reinforcement is
(a) Breadth of flange
(b) Thickness of flange
(c) Breadth of slab
(d) Depth of rib
(a) Breadth of flange
(b) Thickness of flange
(c) Breadth of slab
(d) Depth of rib