Final answer:
To make a saturated solution, you need to add enough solute until no more of it can dissolve in the solvent. In this case, it is not possible to determine the exact amount of KCl that needs to be added.
Step-by-step explanation:
A saturated solution is a solution in which no more solute can be dissolved at a given temperature. To make a saturated solution, you need to add enough solute until no more of it can dissolve in the solvent. In this case, you have already dissolved 10 grams of KCl in 100 grams of water at 30 degrees C. To make a saturated solution, you need to add enough KCl until no more of it can dissolve in the 100 grams of water. Since the question does not specify the solubility of KCl at 30 degrees C, it is not possible to determine the exact amount of KCl that needs to be added. Therefore, none of the given options (a) 10 grams, (b) 20 grams, (c) 90 grams, or (d) 110 grams can be considered as the correct answer.