To prevent cells from either shrinking or swelling you should keep them in an isotonic solution. Isotonic solution is a solution with equal amount of solute and solvent. Therefore, when cells are placed in such a solution they will not lose or gain water, as opposed to hypertonic (more solute than solvent) and hypotonic (more solvent than solute) solutions.
C. 330 m/s is the correct answer.
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The breeding of plants and / or animals to produce fascinating traits.