Which of the following statements states the terms ' activity ' and ' selectivity ' respectively ?

Question

(a) ability of catalyst to increase the chemical reaction ; ability of catalyst to decrease the reaction . (b) ability of catalyst to decrease the reaction ; ability of catalyst to direct the reaction to give particular products. (c) ability of catalyst to decrease the reaction ; ability of catalyst to reverse the reaction to give particular products . (d) ability of catalyst to increase the chemical reaction ; ability of catalyst to direct the direction the reaction to give particular products