Final answer:
A micropipette would most accurately measure 0.1 mL of a liquid.
Step-by-step explanation:
A micropipette would most accurately measure 0.1 mL of a liquid. Micropipettes are designed to quickly and accurately dispense small volumes, and they come in a variety of sizes. They are adjustable and can be used to accurately measure volumes as low as 0.1 mL.
On the other hand, a 50-mL beaker, a graduated cylinder, and an Erlenmeyer flask are not suitable for measuring small volumes with high accuracy. A beaker and an Erlenmeyer flask are used for general mixing and not precise volume measurements. A graduated cylinder can measure larger volumes accurately but is not the best choice for measuring 0.1 mL. A micropipette is the most appropriate instrument for measuring such a small volume accurately.