Answer:
This is a tough one, because all three seem correct. If your lesson has a direct definition of 'observation', I would take a look and see if it applies to any of these.
Step-by-step explanation:
However, in science, an observation is just the starting to point for an experiment or hypothesis. So, if we were to look at the 'starting point' of the journey of this apple, option a is the general starting point. It isn't too specific, but it provides an observation of a process that happens.