[单选题]
If heat is added to a pure substance atx1wfz kw7od v+qc;3p3 a str2lx* 799kpkwu8 w l9 wqgt;wqeady rate,
A. its temperature will begin to rise.
B. it will eventually melt.
C. it will eventually boil.
D. More than one of the above is true.
E. None of the above is true.
