Nuclear fossion hope this helps
Decantation is a process for the separation of mixtures of immiscible liquids or of a liquid and a solid mixture such as a suspension.
Molecules in the paper react differently with Hydronium and Hydroxide.
pH paper deals with acidity and basicity of something. You are correct in thinking that A is the answer. Always go with your gut. don't be like me when I was in college who always second guessed my answers. Good luck with chemistry.
