Step 1: Concept
Vapor pressure and boiling point are inversely related.
Step 2: Meaning
A lower boiling point indicates weaker intermolecular forces, allowing molecules to escape into the vapor phase more easily at a given temperature.
Step 3: Analysis
Comparing the given boiling points, Diethyl ether has the lowest boiling point ($35^{\circ}C$). This means it is the most volatile among the four liquids listed.
Step 4: Conclusion
Because it has the weakest intermolecular attractions, Diethyl ether will exert the highest vapor pressure at room temperature ($25^{\circ}C$).
Final Answer: (C)
