Which of the following reactions is a dehydration reaction?

Predict the major products of acid-catalyzed dehydration of the following alcohols.

(c)

(d)

A vicinal diol has OH groups on adjacent carbons. The dehydration of a vicinal diol is accompanied by a rearrangement called the pinacol rearrangement. Propose a mechanism for this reaction.

Propose mechanisms for the following reactions. In most cases, more products are formed than are shown here. You only need to explain the formation of the products shown, however.

(c)