The time for half life of a certain reaction A → Products, is one hour. When the initial concentration of the reactant A is 2 mol L-1 how much time does it take for its concentration to come from 0.50 to 0.25 mole L-1 if it is a zero order reaction ?
(a) 0.25 h
(b) 1 h
(c) 4 h
(d) 0.5 h