The correct option is B Statement 1 and 2 are correct, and statement 2 is the reason for statement 1.
C4− and C4+ ions are unstable.
C4− is unstable because it would be difficult for the nucleus with just six protons to hold on to ten electrons.
C4+ is unstable because it would require a large amount of energy to remove all the four electrons from its valence shell.
Carbon overcomes this problem by sharing its valence electrons with other carbon atoms or the atoms of other elements to complete its octet.
Thus, both the statements are correct and statement 2 is the correct reason for statement 1.