The covalent compunds consist of discrete molecules.

Answer: Option B

Discrete : individually separate and distinct.
Concrete : existing in a material or physical form; not abstract.
Grouped :put in a group or groups.
Separate : forming or viewed as a unit apart or by itself.
Convoluted : (especially of an argument, story, or sentence) extremely complex and difficult to follow.

Antonym of Discrete is Grouped