Respuesta :
C. hypothesis. He is giving a possible answer to the question "why did the celery crisp when placed in water?"
Answer: Hypothesis
Explanation: The suggestions cannot be said as scientific statements because there is no scientific validation for the those statements.
The hypothesis are the statements that have not been defined by the experiments with proper explanation.
The suggestion given by the student can only be considered as hypothesis because they are not proven experimentally with proper steps of scientific methods.