Carbon is different from many other elements in that * a. it has four electrons in its outermost energy level.
b. it readily bonds with other carbon atoms.
c. it can form single, double, or triple bonds with other atoms.
d. All of the above

The answer is D. all of the above

Explanation: The answer is D. because carbon has four valence electrons, so it can achieve a full outer energy level by forming four covalent bonds. A carbon atom can bond with another carbon atom two or three times to make double and triple covalent bonds between two carbon atoms.

Hope this helps!

d.embryo is the correct one