Polar molecules a. have little attraction for each other. b. are all solids. c. are symmetrical. d. are asymmetrical.

Choice (d) is correct. Polar molecules are asymmetrical.

Polar molecules are those molecules with positive and negative charge centers separated by some distance. These molecules have asymmetrical arrangements of atoms, so there are poles, that is, there are net charges present in the molecule. Water is a great example of a polar molecule. It is composed of two hydrogen atoms and one oxygen atom.

H-O-H

It may look symmetrical, but in reality, there are two lone pairs of electrons on oxygen atom which push the hydrogen atoms away, thereby giving a "bent" geometry to the water molecule.

Non-polar molecules, in comparison, are symmetrical in nature and this symmetry causes a lack of any asymmetric charge centers. Carbon dioxide is a linear molecule and lacks any lone pair of electrons and is thus a non-polar molecule.

Hope this helps.