What should be the concentration range for Kay-5 solution?

The correct concentration range for the Kay-5 solution is 50-100 PPM because this range is established based on the optimal effectiveness of the solution for its intended use. Concentrations within this bracket ensure that the solution is potent enough to deliver the desired results while also maintaining safety standards and avoiding excessive dosage that could lead to diminishing returns or adverse effects. Adhering to this range is important for achieving the best operational outcomes and ensuring compliance with safety regulations in the relevant applications of the Kay-5 solution.