Q: Fact 1: Roots have primary and secondary meristems for growth in length and width. Fact 2: Rulers are used to measure length. Given the two facts above, the growth in what comes from primary and secondary meristems can be measured with a ruler?

I. bushes;
II. years;
III. Trees;
IV. three;
V. roots;
VI. bamboo;
VII. rings;
VIII. a prism;
A:
V.