To measure 1 tablespoonful of potassium chloride solution, which measuring device should be used?

Using a medication cup is appropriate for measuring 1 tablespoonful of potassium chloride solution because medication cups are specifically designed to provide accurate measurements for liquid substances. They often come with measurement markings and are recognized for their use in administering doses of liquid medications. This ensures that the correct volume is measured, which is critical for medications like potassium chloride that require precise dosing to avoid potential toxicity or inadequacy.

In this context, while a tablespoon could informally measure the same volume, it may not have the same level of precision as a calibrated medication cup. An oral syringe, on the other hand, is typically used for smaller volumes and could lead to incorrect dosing for larger quantities. An oral dropper provides an even smaller measurement and wouldn't be suitable for the tablespoonful measurement required in this scenario. The accuracy and design of the medication cup make it the most appropriate choice for measuring a tablespoonful of liquid medication safely and effectively.