Write the structures of the isomers of alcohols with molecular formula $C_4H_{10}O$. Which of these will exhibit optical activity?

(N/A) The isomers of alcohols with molecular formula $C_4H_{10}O$ are:
$1.$ $Butan-1-ol$: $CH_3-CH_2-CH_2-CH_2-OH$
$2.$ $Butan-2-ol$: $CH_3-CH_2-CH(OH)-CH_3$
$3.$ $2-Methylpropan-1-ol$: $(CH_3)_2CH-CH_2-OH$
$4.$ $2-Methylpropan-2-ol$: $(CH_3)_3C-OH$
Among these,$Butan-2-ol$ exhibits optical activity because the $C_2$ carbon atom is chiral,as it is attached to four different groups: $-H$,$-OH$,$-CH_3$,and $-C_2H_5$.