Names of some cpmpounde are given. Which one is not in IUPAC system :

Options

A. `underset("5-Methyl-4-ethylheptane")(CH_(3)-CH_(2)-CH_(2)-underset(CH_(2)CH_(3))underset(|)overset(CH_(3))overset(|)(C)-CH-CH_(2)-CH_(3))`
B. `underset("3-Methyl-2-butanol")(CH_(3)-underset(OH)underset(|)(CH)-underset(CH_(3))underset(|)(CH)-CH_(3))`
C. `underset("2-Ethyl-3-methyl-but-1-ene")(CH_(3)-CH_(2)-underset(CH_(2))underset(||)(C)-underset(CH_(3))underset(|)(CH)-CH_(3))`
D. `underset("4-Methyl1-2-pentyne")(CH_(3)-C-=C-CH(CH_(3))_(2))`.

Answer

A