Given below are two statements; one is labelled as Assertion (A) and the 
other is labelled as Reason (R).
Assertion (A) : AgCl is more covalent than NaCl 
Reason (R) : Polarising power of $A{g}^{+}$  is greater than $N{a}^{+}$  ion. 
In the light of the above statements, choose the most appropriate answer  from the options given below :