The dehydration of tertiary alcohols is relatively simple and can be achieved by heating the alcohol to a high temperature or using a catalyst. The dehydrated product is a mixture of alkenes, with or without carbocation rearrangement. Recall that dehydration process involves removal of a molecule of water. As a result,the OH in the tertiary alcohol will combine with one atom of H from the CH\(_3\) attached to the C atom carrying the OH group, to form water, thereby introducing a C=C. The product of dehydrating a tertiary alcohol is an alkene. Therefore, option D is the correct answer.