Son de origen animal o vegetal, por
Ejemplo las cascaras de frutas y verduras​

b..

is the correct one

explanation:

covalent bonds form as valence electrons are shared between two atoms. lewis structures and structural formulas are common ways of showing the covalent bonding in organic molecules. formal charge describes the changes in the number of valence electrons as an atom becomes bonded into a molecule.

it would only be the stuff in module eight so you need to study all the lessons in that you also could check the flvs

hope this : )