A is false- a solid that forms in a solution is called a precipitate
B is true.
C is false - A solution with any amount of dissolved solute less than the amount required to make a saturated solution is considered to be unsaturated. Whenever a solution contains more solute than it can hold, it is said to be supersaturated.
D is false - a solute can be solid, liquid or gas and it dissolves in a solvent, water is also a solvent.
E is true.