Which of the following statements about the closest packing of spheres in binary ionic solids is false? a. The packing is done in a way that minimizes repulsions among ions with like charges. b. The packing arrangement maximizes electrostatic attractions among oppositely charged ions. c. For spheres of a given diameter, tetrahedral holes are larger than octahedral holes. d. Trigonal holes are so small that they are never occupied. e. None of these.