I believe it would be answer B: character vs. nature conflict
Thank you for posting your question here. It can be considered to be consistent with the given facts. As you know, an hypothesis, much less a theory, is never proven. It can be shown to be consistent with given observations. As new observations are collected, the given hypothesis may have to be modified.
If the celery became crisp when it was soaked in ice water, then clearly that the water has rehydrated the celery is a reasonable hypothesis. But did it have to be ice cold water? Would room temperature water work? What about boiling water?
And thus most of the time, the success of an hypothesis leads to the design of new experiments to test and expand the original hypothesis.
