Assertion: Glassy solids have a sharp melting point.
Reason: The bonds between the atoms of glassy solids get broken at the same temperature.
A. Both assertion and reason are correct and the reason is the correct explanation of the assertion.
B. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
C. The assertion is correct but the reason is incorrect.
D. Both the assertion and reason are incorrect.

Hint: Amorphous solid is basically a non-crystalline solid in which the atoms and molecules are not organized in a definite lattice pattern. Examples of amorphous solids are glass, plastic, gel, etc.

Complete step by step solution:
We know that glassy solids are amorphous in nature and amorphous solids have the property that they do not possess a sharp melting point. In a glassy or amorphous solid the bond strengths between different molecules or atoms are not consistent (inequal).

Hence, these bonds undergo thermal degradation(break) at different values. This is the reason these amorphous solids do not possess a fixed melting. Therefore, we can conclude that both the assertion and reason are incorrect.

Hence, option D is the correct answer.

Note:The solids are divided into two types based on the crystal structures : amorphous solids and crystalline solids. Crystalline solids are solids whose particles are arranged in a specific or regularly repetitive pattern. Quartz, diamond, sugar, mica, and calcium fluoride are examples of crystalline solids. There are seven crystal structures; they are triclinic, monoclinic, orthorhombic, tetragonal, trigonal, hexagonal, and cubic.