C3H7OH ( PROPANOL) ⇒ 97ºC

 C7H16 ( HEPTANE ) ⇒ 98.42ºC ;and

C4H10 ( BUTANE ) ⇒ -1ºC

ALTERNATIVELY,

In general, the higher the molecular mass of a substance, the higher its boiling point. This is because larger molecules have more intermolecular forces of attraction, which must be overcome for the substance to boil. If the molecular masses of each of the compounds are calculated, propanol (60g/mol), heptane(100g/mol) while butane(58g/mol). 

Arrangement in increasing order will be  C4H10 → C3H7OH → C7H16 - Option D