Final answer:
A 100 mL volumetric flask is the glassware used to prepare a 100 mL, 12% solution with precise volume and concentration.
Step-by-step explanation:
The type of glassware used to make 100 mL of a 12% solution is D) Volumetric flask. Volumetric flasks are designed for making up solutions to a precise volume, ensuring accuracy and consistency in the concentration of a solution. When you need to prepare 100 mL of a 12% solution, filling a 100 mL volumetric flask to the mark with your solution components will provide the desired accuracy.
Graduated cylinders, while useful for measuring volumes more flexibly, are not as accurate as a volumetric flask for preparing solutions of a specific concentration. Burets and pipettes are more often used in titration or when adding a precise volume of liquid to a mixture, rather than for the initial preparation of a volume-specific solution.