The graph displays the temperature over time for an unknown substance. Which of the following correctly identifies segment XY and why?

A.
Melting, because the substance has a freezing/melting point of 290°C.

B.
Melting, because energy is being added, but the temperature is not changing

C.
Vaporization, because the substance cannot be heated beyond a temperature of 290°C.

D.
Vaporization, because energy is being added, but the temperature is not changing.

hèllo, sorry i really need some more points so if you need this qustion answered than retype it

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i just did this and got a 100.

answer: good job it's all correct !

explanation: