1) b: heptane.
2) d: 2-methylpropane.
3) a: 2,2-dimethylpropane.
4) c: 2-methylbutane.
5) c: 2,4-dimethylhexane.
6) a: 3-ethyl-5-methylheptane.
7) d: 2,2,3-trimethylbutane.
8) a: 4-(tert-butyl)heptane.
9) a: 5-ethyl-3-methyl-4-propyloctane.
10) c: 3-methyl-4-(propan-2-yl)heptane.