Answer: it is for a functional group alkyne (triple bond)
Step-by-step explanation:
As we know that aliphatic hydrocarbons are saturated and unsaturated hydrocarbons.
Unsaturated hydrocarbons have triple and double bonds in their structures.
Rule for naming alkyne: prefix+ root word+ suffix
Example, 2-butyne
Prefix- 2
Root word: but
Suffix- yne
2-butyne
Here yne is called as suffix.
Hope it will help you.