Correct Answer - B
Ethene gives `1^@` alcohol (ethanol) , propene gives `2^@` alcohol while 2-methylpropene gives `3^@` alcohol.
`underset"Ethene"(CH_2=CH_2)underset((ii)H_3O^+)overset((i)Conc. H_2SO_4)to underset"Ethanol"(CH_3CH_2OH)`
`underset"Propene"(CH_3-CH=CH_2)underset((ii)H_3O^+)overset((i)Conc. H_2SO_4)to underset(2^@ "Alcohol")(CH_3-CHOH-CH_3)`
`underset"2-Methylpropene"(CH_3-oversetoverset(CH_3)|C=CH_2)underset((ii)H_3O^+)overset(Conc. H_2SO_4)to underset(3^@ "Alcohol")((CH_3)_3COH)`
Thus , either `2^@` or `3^@` alcohol is formed.