A schematic of the solution is shown below. The information from the question is given in black. Deductions directly from this information are given in red. Points that provide potential key information are shown in green which leads to the structures which are linked via the blue arrows to show the path required to work them all out. There are, of course, other possible thought pathways.

TEMPORARY SOLUTION
A = 2-methyl-1,3-butadiene
B = 1-methylcyclohexene
C = 2-methylcyclohexanol
D = 2-methylcyclohexanone
E = 1,2-dimethylcyclohexanol
F = 1,2-dimethylcyclohexene
G = 2-methylmethylenecyclohexane

Note A can't be 1-methyl-1,3-butadiene and B can't go 3-methylcyclohexene because that would give a larger mixture of isomsers for C, D, E, F etc.