To observe the effect of concentration on the conductivity electrolytes of different nature were taken in two vessels A and B. A contains weak electrolyte NH4OH and .B contains strong electrolyte NaCl. In both containers, concentration of respective electrolyte was increased and the observation is
(a) in A conductivity increases, in B conductivity decreases
(b) in A conductivity decreases, while in B conductivity increases
(c) in both A and B conductivity increase
(d) in both A and B conductivity decrease.