$1)C_4H_8+H_2O\rightarrow \begin{cases}CH_3CH_2CH_2CH_2OH \\ CH_3CH_2CH(OH)CH_3\\(CH_3)_2CHCH_2OH\\(CH_3)_3COH \end{cases}\Rightarrow Chon:B$$2)$
$CH_3CH_2CH_2CH=CH_2 ; cis,tran-CH_3CH_2CH=CHCH_3$
$(CH_3)_2CHCH=CH_2 ; (CH_3)_2C=CHCH_3 ; CH_2=C(CH_3)CH_2CH_3$
$\Rightarrow Chon:D$