The correct option is C Inter-molecular hydrogen bonding in alcohols
An ether is more volatile than an alcohol having the same molecular formula. This is due to inter-molecular hydrogen bonding in alcohols. The inter-molecular hydrogen bonding in alcohols leads to molecular association and raises boiling point. Due to this, alcohol becomes less volatile. The inter-molecular hydrogen bonding is not possible in ethers as in ethers, H atom is not attached to electronegative O atom.