Identify the organic compound having highest boiling point from...

The boiling point of organic compounds depends on the strength of intermolecular forces.

All the given compounds have comparable molecular masses (approximately $73-74 \text{ g/mol}$).

Amines form weaker hydrogen bonds compared to alcohols and carboxylic acids because nitrogen is less electronegative than oxygen.

Carboxylic acids form stronger intermolecular hydrogen bonds than alcohols and typically exist as dimers in the liquid phase, which significantly increases their effective molecular mass and boiling point.

Therefore, propanoic acid ($\text{C}_2\text{H}_5\text{-COOH}$) has the highest boiling point among the given compounds.

Answer: $\text{C}_2\text{H}_5\text{-COOH}$