Which element is composed of molecules that each contain a multiple covalent bond

A. Chlorine

B. Fluorine

C. Hydrogen

D. Nitrogen

Your answer is D: nitrogen

Nitrogen has got multiple covalent bonds

Explanation:

A nitrogen atom can fill its octet by sharing three electrons with another nitrogen atom, forming three covalent bonds, a so-called triple bond. Since Nitrogen has five valence electrons, so it needs three more valence electrons to complete its octet. Therefore Nitrogen is the only atom which has multiple covalent bonds in the given options.