c)  Incorrect.  CCl₄ is a tetrahedral molecule.  Each of the bonds is polarized toward the chlorine atom.  Adding together any two bond dipoles
             gives a subtotal sum halfway between them directed away from the central carbon atom.  Adding together the other two bond dipoles
            gives a second subtotal sum halfway between them directed away from the central carbon atom.  These two subtotal sums are exactly
            opposite each other (tail-to-tail) and will therefore cancel each other out making the molecule nonpolar.  CH₂Cl₂ is also a tetrahedral
            molecule.  Each of the C-Cl bonds is polarized toward the chlorine atom and the C-H bonds are polarized toward the carbon atom.  Adding
            together the two C-Cl bond dipoles gives a subtotal sum halfway between them directed away from the central carbon atom.  Adding
            together the two C-H bond dipoles gives a subtotal sum halfway between them directed toward the central carbon atom.  These two subtotal
            sums do not cancel each other out (in fact, they reinforce each other) so the molecule is polar.  CHCl₃ is also a tetrahedral molecule.  Each of
            the three C-Cl bonds is polarized toward the chlorine atom while the C-H bond is polarized toward the carbon atom.  Adding together two
            C-Cl bond dipoles gives a subtotal sum halfway between them directed away from the central carbon atom.  Adding together the third C-Cl
            bond and the C-H bond dipoles gives a subtotal sum which won't cancel out the other subtotal sum (since the combination is different) thus
            the molecule is polar.