Carbon can also bond with other
four atoms because of its outer shell (valence shell) that has four electrons.
This is the reason why organic molecules can be so large because of this
bonding. Suppose you have a compound of CCl4. You know that chlorine can only
share 1 electron because 7 of its electrons are filled. Also, in carbon, it can
only share 4 electrons because 4 of it are already filled. That is why carbon
needs four chlorine to form CCl4. The answer is letter B.