In a singly reinforced beam, if the stress in concrete reaches its allowable limit later than the steel reaches, its permissible value, the beam section is said to be
(a) Under-reinforced section
(b) Over-reinforced section
(c) Critical section
(d) Balanced section
(a) Under-reinforced section
(b) Over-reinforced section
(c) Critical section
(d) Balanced section