Select a correct structural characterization for the pair:

$2-$methoxypropane and $1-$butanol

Select one:

a$.$ represent the same molecule

b$.$ have the same number of carbon atoms but a different number of oxygen atoms have the same number of carbon atoms and the same number of oxygen atoms but are not isomers

d$.$ have the same number of oxygen atoms but a different number of carbon atoms

e$.$ are isomers