Question

Functional group of C2H6O

Answer 1

It is an alcohol or an ether ( functional isomerism exists for this compound)

Answer 2

It can be an alcohol .
Functional Group = OH
(see attachment ; upper structure)
___________
H3C-O-CH3
Functional Group is ="—OCH3"
(Methoxy group)
it can represent "Ether" also.
(see attachment ;Lower structure)
__________
hope it helps!