Answer:
1) Acid
2) heat
Step-by-step explanation:
Dehydration is a type of chemical reaction in which water is removed from an alkanol to yield one or more alkenes.
The reaction normally commences with a protonation of the -OH group by a proton from the acid. Water is always a good leaving group so it quickly departs creating a carbocation. The removal of a proton yields the alkene.
The major product is the one in which there is greater substitution around the C=C double bond.