$\begin{array}{1 1} \text{(a) Because valency of iron in ferric chloride is equal to that of potassium in KCl}\\ \text{(b) Because valency of iron in ferric chloride is 2+, whereas that of potassium in KCl is 1+ } \\ \text{(c) Because valency of iron in ferric chloride is 5+, whereas that of potassium in KCl is 1+} \\ \text{(d) Because valency of iron in ferric chloride is 3+, whereas that of potassium in KCl is 1+} \end{array} $
