When the moon apprears to be growing larger it is said to be?

The graph shows the solubility of several different salts in water, across a range of temperatures. according to the graph, which salt can dissolve at a concentration of about 60 g/100 cm3 of water at 40 degrees celsius?

I’m stuck on this question cuz i’m stupid sksksksk

Which label correctly identifies what x represents in the concept map?