Final answer:
The information collected from observing fish growth over a month would be categorized as data, which is essential for scientific investigation and hypothesis testing.
Step-by-step explanation:
Information gathered from observing the growth of a fish over a month is called data. Data refers to the observations collected in a scientific investigation in order to test a hypothesis. These are the actual measurements or other observations made during an investigation, which are then analyzed and interpreted to decide whether they support or reject a hypothesis. The other provided options of inferences, variables, and hypotheses will not be the correct options and so will not be chosen.