Answer: B. Plant Growth
Explanation: Basically it is just giving you the main idea of how long and how tall it grows everyday. You can see how it grows from the Plant growth line to the day line. It grows 2 cm on day one, then on Day two grows to 3cm. Day three, 5 cm, Day four 6 cm and Day five, 8cm. It's just agood way to plot and keep track of data and help you. Not hard but sometimes it can be.
I hope this helps you!