Let's define what an observation is:
An observation is a quantity or quality of something that you can see without making inference.
Let's apply this definition to our problem:
We are trying to find which is the observation between the three.
0. A. You conclude that the season is changing. - This would be ,inference,. You are "guessing" what ,will happen,, not something that ,has happened,. You don't know for sure that the season is changing.
,1. B. You hypothesize that the plant will grow 1 mm every day for a week. - This would also be ,inference,. The key word is ,hypothesize,; you are making an ,educated guess,.
,2. C. You measure a plant's height every day for a week. - This would be an ,observation, since you can ,quantitatively ,measure and ,observe, that plant's heigh every week.
Therefore, our best answer choice is C. You measure a plant's height every day for a week.
