The temperature point at which solid, liquid and gaseous states may stay together is known as

Correct answer: (d) triple point

Explanation

The triple point is the unique temperature and pressure where solid, liquid and gas phases of a substance coexist in equilibrium.

For water it occurs at 0.01°C and a pressure of about 4.58 mm Hg.

Boiling, melting and freezing points involve only two phases, not all three together.