Answer:
Option B
Explanation:
A structural isomer of an organic compound refers to a compound that has the same molecular formula, but a different arrangement of atoms in the carbon chain.
Butanol has the molecular formula C4H9OH. We can now explore the options to see if any of them have the same molecular formula.
Option A has no oxygen in it, so we can rule it out
Option B has 4 carbon atoms, 9 hydrogen atoms and 1 oxygen atom as well as single Chain branches. This makes it the structural isomer of Butanol ( C4H9OH).
Option C has only 3 carbon atoms which rules it out as being an isomer.
