To determine which bond between atoms has the greatest polarity we must look at the difference in electronegativities of the elements involved in the bond. The greatest difference in electronegativity will correspond to the most polar bond.
The electronegativities of each element can be found in the periodic table. The difference in electronegativities will be:
We see that the element pair that has the greatest difference in electronegativity is carbon (C) and fluorine (F).
So the bond between atoms that has the greatest polarity is C-F. The answer is the third option. C-F