28. Evaluate the following statements: 1- Water is a pure substance at it boils at a fixed boiling point. II- Components of mixtures are combined by a strong chemical bond. III- Pure substance melts completely within a short time. IV- Completely dissolved salt in water can be separated by filtration. Which statements above correctly describe pure substance and mixture? A. I and II C. II and HII B. I and III D. II and IV​