One of the following questions is true; the rest are false. Please identify the true statement in the enumeration below.
(a) Lone pairs are an exception to the rules for Lewis dot structures.
(b) A double bond consists of two sigma bonds.
(c) Tetrahedral molecules are more stable than other molecular geometries.
(d) A pi bond allows rotation about the sigma bond axis.
(e) None of the above.
Answer: None of the above.