Concept:A mixture is a physical combination of two or more substances that are not chemically joined.
Explanation:Blood contains water, proteins, fats, sugar, vitamins, hormones, and enzymes.
These components keep their individual properties and can be separated by physical methods.
Therefore, blood is a mixture, not a pure compound.
Common salt, sand, and washing soda are generally considered pure substances or compounds, not simple mixtures.
Answer:B. Blood