The IUPAC name for the compound CH\(_3\)C ≡ CHCH(CH\(_3\))\(_2\) is 4-methylpent-2-yne.

First: Name the longest Carbon atom chain, with reference to the shorter route of the position of the triple bond ≡ i.e pent-2-yne (5 Carbon atom with ≡ on C-2)

Secondly: name the substituent functional group. i.e the CH\(_3\) - methyl on C-4 ( 4- methyl)

Thirdly: Combine second and first steps together. i.e 4-methyl and pent-2-yne.

IUPAC Nomenclature of the compound above is 4-methylpent-2-yne - option B