#1.# #"Intrinsic solubility"#. In general a polar solvent will solvate polar and ionic solutes, and poorly solvate (i.e. dissolve) apolar solutes.
#2.# #"Temperature:"# dissolution is in general a bond breaking process. The higher the temperature, the greater (and faster) the dissolution.
#3.# #"Sample size"#: clearly a pulverized solute, i.e. a fine powder, will have a greater surface area than a block of solute, and thus its rate of dissolution should be greater.
I would be interested to see your teacher's answer to this question, to see if these answers agree with his or hers, so I would be grateful if you would oblige. I am reminded of the old Groucho Marx quip:
#"Those are my principles; if you don't like them, I have others......"#