In this task, you are given two facts, and a multiple-choice question. Based on the given facts, answer the question with index of the correct option (e.g, "A").
Q: Fact1: Cells vary in size as well as shape, but all cells are very small., Fact2: Basic unit of the plant body is the cell., Question: What may vary in size as well as shape, but all are very small? (A) keeping food fresh for long periods of time (B) disease-causing microorganisms (C) A solid geometric shape (D) Unequal radiation absorption (E) Small countries. (F) Shapewear. (G) A water well. (H) Basic units of the plant body.
A:
H