Verified answer

An empirical formula is the most simplified formula for the molecule, essentially showing the ratio of the substituents to one another.

What you want to do is take the largest common factor of them and factor it out.

A) C6H6 (Largest Factor is 6) Empirical formula -> CH

B) C2H4 (Largest Factor 2) -> CH2

C) C4H12 (Largest Factor 4) -> CH3

D) CH4 This is already reduced to its minimum -> CH4

E) C3H6 (Largest Factor is 3) -> CH2

B and E are identical.

B and E