Answer: The correct answer is electron pairs and electrons.
Step-by-step explanation:
Covalent bond is defined as the bond which is formed by the sharing of electrons between two atoms that are forming a compound.
A bond is formed when two electrons are shared between the atoms. In covalent bond, the atoms are held together by the attraction of electron pairs that are present between them.
Covalent bond can be single, double or triple bond. A single bond is formed when 2 electrons (1 electron pair) are present between the atoms.
A double bond is formed when 4 electrons (2 electron pairs) are present between the atoms.
A triple bond is formed when 6 electrons (3 electron pairs) are present between the atoms.
Hence, the correct answer is electron pairs and electrons.