Carbon forms four covalent bonds by sharing its four valence electrons with four univalent atoms, e.g. hydrogen. After the formation of four bonds, the carbon attains the electronic configuration of:
A. Helium
B. Neon
C. argon
D. Krypton

Hint: Carbon is a tetravalent atom which shares its four valence electrons with the other atom to form four covalent bonds. After the formation of a chemical bond the carbon attains the new configuration by adding four electrons to the valence shell.

Complete step by step answer:
The atomic weight of a carbon atom is 6. The electronic configuration of carbon is \[1{s^2}2{s^2}2{p^2}\]. The valence electron of carbon is 4. The carbon cannot form an anion or a cation by losing electrons or gaining the electrons as very high energy is required for that therefore it shares its four electrons with the four univalent atoms to form a chemical bond usually covalent bond is formed.
When the four bonds are formed, four more electrons are added in the valence shell of the carbon and the resulting electronic configuration will be $1{s^2}2{s^2}2{p^6}$.
By seeing the new generated electronic configuration obtained by sharing the electrons with a univalent atom to form the covalent bond we can say that total 10 electrons are present in the orbitals which means the atomic number of atoms is 10. Thus, the element with atomic number 10 is neon.
Thus, after the formation of four bonds, the carbon attains the electronic configuration of neon.
Therefore, the correct option is B.

Note: Neon is an inert gas element as it follows octet rule which says that to attain stability the element should possess 8 electrons in its valence shell and neon contains 8 electrons in the valence shell. Neon is highly stable and cannot share its electrons to other elements.