CTET Class I to V 9 Jan 2023 Paper

Rini asked his teacher, "Why are the stems of plants round and not square-shaped?" What should the teacher do?
A. Teacher should tell students that they will learn about this in higher classes.
B. Teacher should explain students that the reason of round stems is the gravity.
C. Teacher should ask students to think about the reason for the round shape of stem.
D. Teacher should take students for a garden visit and ask to observe the shape of various stems.