Hello!
Your answer would be polar covalent.
Covalent bonds are where two atoms come together, and share electrons between each other, and are therefore, bonded.
In some cases of molecules that are bonded with a covalent bond, one of the atoms is more, you could call it selfish, and takes more of the electrons. A prime example of this is H20, or water. One of the atoms takes the electrons for longer, and therefore has a more negative charge because electrons are counted as negative charges.
This bond where an atom "hogs" electrons, is called a polar covalent bond, respective to the changing charges for the atoms.
So your answer is d.
Hope this helped!
