Answer: -
D. Network
Explanation: -
Diamond is an allotrope of carbon. In diamond each carbon atom makes four bonds to other carbon atoms.
They exist in tetrahedral shape.
Diamond has strong covalent bonds. They extend in all the three dimensions
Such covalent bonds are called network covalent bonds. They require significant amounts of energy to break.
The greater the energy, the larger the frequency and the shorter (smaller) the wavelength. Given the relationship between wavelength and frequency — the higher the frequency, the shorter the wavelength — it follows that short wavelengths are more energetic<span> than long wavelengths.</span>