Easy to understand all the pairs of compounds are drawn below,
Answer:
Option-A (Butane and 2-Methyl propane)
&
Option-D (Pentane and 2-Methyl butane)
are the isomers of each other.
Explanation:
Isomers are those compounds which have same molecular formula but different structural formula.
In given options, Option-B are not isomers because they are the same compounds, just flipped on 180°.
Option-C are not isomers because the number of carbo and hydrogen atoms are not same.
Option-E are not isomers because the number of hydrogen, carbon and oxygen atoms are not same.
