Answer:
C. recording the outdoor temperature
Step-by-step explanation:
A scientific investigation or a scientific research may be defined as a method to test and acquire knowledge by observing and learning certain points. It is a way of systematic approach to find an answer or solution to a problem by making observations and carrying out a scientific experiment using the parameters.
In the context, a group of students recording the outside temperature may be considered as a scientific investigation as they are making some observation that may effect something or it can help finding out some of the solution or answers to their questions.