The diagrams illustrate two distinct compounds. What is: • the total number of structural isomers, including compound 2, that could be produced by adding a second methyl group to the ring of compound 1, • the number of $\pi$ electrons present in each compound?
- Anumber of isomers: 3; number of $\pi$ electrons: 2
- Bnumber of isomers: 3; number of $\pi$ electrons: 4
- Cnumber of isomers: 5; number of $\pi$ electrons: 2
- Dnumber of isomers: 5; number of $\pi$ electrons: 4