Tanker Familiarization Liquefied Natural Gas (LNG) Practice Exam

Hydrocarbons are grouped by the type of carbon–carbon bonds they contain: single bonds, double bonds, or triple bonds. This leads to three main families: alkanes are saturated hydrocarbons with only single bonds; alkenes have at least one carbon–carbon double bond and are unsaturated; alkynes have at least one carbon–carbon triple bond and are also unsaturated. Each family has distinct reactivity and properties based on those bond types.

The best choice lists alkane, alkene and alkyne as the three hydrocarbon families, matching this categorization by bond type and providing the three fundamental families.

The other options don’t fit because they either name individual hydrocarbons (which would belong to one family, not three) or mix categories that aren’t three distinct bonding-based families (aromatic/aliphatic classifications or saturation concepts that don’t form the standard three-family grouping).