- Common salt
Of the given options, sugar C12 H22 O11 is the most soluble in water H2 O, followed by common salt NaCl, camphor C10 H16 O, and sulphur S8 in that order. Water H2 O is called a universal solvent because it dissolves the majority of compounds present in the earth’s crust. Sugar C12 H22 O11 is a polar molecule that readily dissolves in water due to the water molecule’s ability to form hydrogen bonds with the polar sugar molecule, making it highly soluble. Common salt NaCl is also a polar molecule, but its solubility is slightly lower than that of sugar C12 H22 O11. Camphor C10 H16 O is a nonpolar molecule and has low solubility in water H2 O. Sulphur S8 is also a nonpolar molecule and is only slightly soluble in water H2 O.
Therefore, the answer is c. Sugar.