The reason carbon forms four bonds is to achieve:

• A. To have enough electrons
• B. To gain a positive charge
• C. To reduce its size
• D. To become a noble gas

Answer: (A)

Carbon forms four covalent bonds because it seeks a full outer electron shell. It has four valence electrons, so by sharing electrons in bonds it can achieve eight electrons around the atom, giving a stable, octet-like configuration. That drive—to have enough electrons to fill the valence shell—is what explains why carbon forms four bonds. The other ideas aren’t the main reason: gaining a positive charge isn’t how bonding works for carbon in these compounds, reducing the atom’s size isn’t the goal, and becoming a noble gas is a byproduct of reaching a full shell, not the motivation for bonding itself.