1) c: ethene.
2) b: 2-methylprop-1-ene.
3) a: 2,4-dimethylpent-2-ene.
4) b: 6-ethyl-5-methylnon-3-yne.
5) d: 2-methyl-4-methylenehexane.
6) b: propyne.
7) d: nona-1,4,7-triene.
8) c: 6-methylocta-2,4-diyne.
9) d: 4-ethyl-3-methylhex-3-en-1-yne.
10) a: 3-ethyl-2-methylhex-2-en-4-yne.