Final answer:
The volumetric flask is the right choice for preparing a solution with a known concentration because it is calibrated to hold a precise volume. It provides a higher level of precision compared to other options like the graduated cylinder or buret.
Step-by-step explanation:
The volumetric flask is the right choice here because it is designed to deliver a single volume accurately when filled to the mark. It is specifically calibrated to hold a precise volume, making it ideal for preparing stock solutions with known concentrations. The other options, such as the graduated cylinder and buret, are designed to deliver variable volumes and may not provide the same level of precision.