# Which one of the following pairs of reactants does not form oxygen when they react with each other?

(a) $F_2,NaOH$ solution (hot, conc.)

(b) $F_2,H_2O$

(c) $Cl_2,NaOH$ solution (cold,dilute)

(d) $CaOCl_2,H_2SO_4$ (dilute, small amount)