At triple point the substance co-exists in 1. Liquid phase 2. Solid phase 3. Vapour phase Select the correct answer using the code given below:

In thermodynamics, the triple point of a substance is the unique combination of temperature and pressure at which its three states of matter—solid, liquid, and gaseous phases—coexist in stable thermodynamic equilibrium. According to Gibbs' phase rule, for a single-component system like pure water, the coexistence of three phases results in zero degrees of freedom, meaning this state can only occur at one specific point on a phase diagram. For example, the triple point of water occurs at exactly 273.16 K (0.01 °C) and a pressure of 611.73 Pa, where ice, liquid water, and water vapor are present simultaneously. At this intersection, the curves for sublimation, fusion, and vaporization meet, representing the only condition where all three phases are in equilibrium. Therefore, all three phases (liquid, solid, and vapour) co-exist at the triple point.