I would go with B. The elements of sugar and water have been known for a long time, so A is irrelevant. Mixtures can contain compounds- most of the time mixtures are composed of compounds mixed together, so C is false as well. Chemical formulas are designed to handle different proportions- that's why they have the numbers before the chemical name, such as 2H2O. B is your best bet for this one, as a mixture is more than one chemical combined but not bonded.
<span> When a sodium atom transfers an electron to a chlorine atom, forming a sodium cation (Na+) and a chloride anion (Cl-), both ions have complete valence shells, and are energetically more stable</span>
