Which statement best explains why carbon is present in so many kinds of molecules? it is abundant on earth. it can form four covalent bonds. it has valence electrons. it can become an ion.

The correct option is IT CAN FORM FOUR COVALENT BONDS.
Carbon is capable of forming four covalent bond in order to attain the octet form, this gives it the ability to combine with different elements in different ways. The ability to combine with different elements makes carbon to be abundant on the earth, because it is found in variety of different substances.