Non-metals are brittle while the metals are ductile. Why? 

As is well known, a material's qualities are greatly influenced by the kinds and depth of bonds that form between its constituent atoms. We also know that unlike non-metals, metals have delocalized electrons in their orbitals that are free to migrate.

As is well knowledge, metals are often composed of metallic bonds that comprise massive cations surrounded by many mobile, or free-moving, electrons.
We are aware that the positively charged cations and negatively charged delocalized electrons from the metal's outermost valence shell interact electrostatically to create these metallic connections, creating a regular layer that allows electrons to travel from one location to another.

All of the atoms are held together by these electrons, which act as glue. When surrounded by a sea of electrons, metal ions experience a powerful electrostatic force of attraction that is both powerful and flexible. Therefore, they may be pulled into wires and flattened into sheets when we apply force, and they are difficult to break. As a result, natural metals like iron become ductile.

However, as non-metals are created by weak attractive forces and are thus quickly destroyed by the application of external force, they are often not rolled into wires. Non-metals are fragile because bond formation occurs to a reduced level. Many non-metals' molecules are bound together by weak attraction forces rather than real bonds.

Therefore, the correct answer is (A).