Answer:
The correct answer is option D "the two students should share a pencil between them".
Step-by-step explanation:
When a covalent bonding between two chlorine atoms occurred each chlorine atom contributes one electron to the bonded pair shared by the two atoms (attached figure). This happens because the two chlorine atoms are attracted to the same pair of electrons. Each chlorine atom gives an electron the other and as a result they form an electron core with an argon electron configuration.