Which of the following types of isomerism is exhibited by the ethers?

A. Chain isomerism 

B. Functional isomerism 

C. Positional isomerism 

D. Metamerism 

B,D

The correct answer is option 2. B,D.

Ethers show two types of structural isomerism:

1. Functional isomerism: Ethers and monohydric alcohols have same general formula C_nH_2n+2O and are, therefore, functional isomers. For example, molecular formula C2H6O has two functional isomers 

2.Metamerism: This is due to the difference in the nature of the alkyl group attached to the oxygen atom without changing the molecular composition. For example, molecular formula C₄H₁₀O can have three isomeric ethers (or metamers) as: