Total of four alcohols can be made with a similar chemical formula. Which are butan-1-ol , butan-2-ol, 2-Methylpropan-1-ol, 2-Methypropan-2-ol.

Out of this four only butan-2-olhas a chiral (four different groups are attached) carbon atom.

Thus, all other options are wrong.

butan-2-ol structure

butan-1-ol structure

2-Methylpropa-1-ol structure

2-Methylpropan-2-ol structure