Answer:
(a) boiling point
(d) density at a given temperature and pressure.
Explanation:
Isomers are compounds that have the same molecular formula but different structural formulas. They differ in chemical and physical properties depending on the type of isomerism displayed by the compounds.
The compounds stated here are structural or constitutional isomers hence they possess different boiling points and densities at a given temperature and pressure owing to structural differences in the molecules.
Since they have the same molecular formula, they must yield the same result during combustion analysis and they must have the same molecular weight.
