I do not understand your question, what is the question, name what??
A serial dilution is the stepwise dilution of a substance in solution. Usually the dilution factor at each step is constant, resulting in a geometric progression of the concentration in a logarithmic fashion.
Answer: A. Limestone rocks dissolving in water
Explanation:
B: This is a physical change; it changes an object physically rather than chemically. It does not change the composition of the concrete, only the shape.
C: This is also a physical change because the water is just dragging sand with it, but not actually changing the composition of it.
D: Similar to option B, this is an example of physical weathering because the ice only divides the rock into different parts but doesn't change the composition or complexity of it.