can anyone explain how do we knew we needed to use the superheated vapor table for the T=100 and P=1bar without telling us? How do we identify which steam table to use?

A piston-cylinder assembly contains 2kg of water at 100C and 1 bar. The water is compressed to a saturated vapor state where the pressure is 2.5 bar. During compression, there is a heat transfer of energy from the water to its surroundings having a magnitude of 250kJ. Neglecting changes in kinetic energy and potential energy, determine the work, in kJ, for the process of the water