The compound in option (1) is pentane-2,4-diol. Loss of two water molecules under acid catalysis gives penta-1,3-diene — a fully conjugated diene whose stability provides a strong thermodynamic driving force for the reaction.

The other options either lack the geometry needed to form a conjugated product or carry an electron-withdrawing nitro group that destabilises the developing carbocation, both of which make dehydration less favourable.