Iodine crystals are(a) Metallic solid(b) Ionic solid (c) Molecular solid(d) covalent solid

Iodine crystals are classified as molecular solids.

Explanation:
Molecular solids are composed of molecules held together by weak intermolecular forces such as van der Waals forces, dipole-dipole interactions, or hydrogen bonding.
Iodine (I₂) exists as discrete diatomic molecules (I₂) in its solid state. These molecules are held together by weak van der Waals forces (specifically London dispersion forces), which are characteristic of molecular solids.
Let's briefly look at the other types of solids for comparison:

Metallic solids consist of metal atoms and are held together by a "sea of electrons" (metallic bonding), which is not the case for iodine.
Ionic solids are composed of ions held together by ionic bonds (e.g., NaCl), but iodine is not made of ions in its solid state.
Covalent network solids (or covalent solids) have atoms connected by covalent bonds in a continuous network (e.g., diamond, quartz). Iodine does not form such a network in its crystalline form.
Therefore, iodine crystals are classified as molecular solids.

The correct answer is: (c) Molecular solid.