Final answer:
The word that describes both 'reed' and 'measuring stick' is canon, but the term papyrus is associated with a reed-like plant used as a writing surface in ancient times. The correct option is a.
Step-by-step explanation:
The word that means 'reed' or 'measuring stick' is canon (option a).
However, 'papyrus' (option b) is associated with a reed-like plant, and it refers to the paper-like material created by overlapping layers of its pith, pressing them, and polishing them. This material was used in ancient times as a writing surface.
To add more context using an example, the earliest known script, cuneiform, was written by pressing a stylus made of reed into wet clay. This technique was different from using papyrus, which involved layering and processing the pith of the papyrus plant.
Hence, Option a is correct.