Ineed with this p. s: my teacher said to answer the question like this, "at any given temperature is more soluble than "

Part 1.

Substance B  

It is soluble in water because after change in temperature some amount is dissolved that is why a change is seen in amount of undissolved material.

Part 2.

The Data helped me to determine solubility of both substances by showing that how much variation was there in solubility by altering the temperature. The Substance which is soluble shows variation and the insoluble one doesn't show.