Please help me find the answer

Solution:
9 a) At point A: The substance is in the solid state.  
        At point B: The substance has starts to melt. At this point it exists in both the solid and liquid state.  
        At point C: The substance is in the liquid state. 
        At point D: The substance begins to boil. At this point it exists both in the liquid and gaseous state.
(b) The melting point of the substance is 15°C
(c) The boiling point of the substance is 110°C
(d) The A₁ to B₁ and D₁ to D₂. Temperature remains constant in this region
(e) From A₁ to B_1​​​- Latent heat of fusion.
                D₁ to D₂ - Latent heat of vaporisation.