Select the incorrect statement from the following option.

Question

$\begin{array}{1 1} \text{(a) Every pure solid crystalline substance has a characteristic and unique melting point} \\ \text{ (b) Impure sample of substance has different melting point} \\ \text{ (c) Two different pure substances have same melting points} \\ \text{ (d) Melting point serves as the criteria of purity of a solid substance} \end{array}$