The correct option is D intermolecular hydrogen bonding in alcohols
An ether is more volatile than an alcohol having same molecular formula because intermolecular hydrogen bonding in alcohols.
The −OH group of alcohol can form intermolecular hydrogen bonds wheres −O− group of ethers cannot form hydrogen bonds. Hydrogen bond formation is possible when H atom is attached to electronegative N, O or F atom. Intermolecular hydrogen bonds leads to molecular association.