Answer:
D: 60 grams.
Step-by-step explanation:
If you look at the x-axis and where it says 50 degrees Celsius, you can see that it takes 20 grams of solute to be saturated at 100 GRAMS of solvent. However, the question is asking for the amount of solute to saturate a 300 GRAM solution.
This means you will have to multiply the amount of solute needed at 100 grams by 3 to get you to the amount needed for 300 grams.
20 times 3 will get you to your answer, 60 grams.