Final answer:
In Tae's investigation, the Independent Variable is the time spent on social media on the phone, and the Dependent Variable is the anxiety levels, indicating the cause-and-effect relationship being studied.
Step-by-step explanation:
In scientific research, including investigations conducted by students like Tae, it is fundamental to identify the Independent Variable (IV) and the Dependent Variable (DV). The Independent Variable is the 'driver' that creates change, which in a research setting is manipulated or controlled by the experimenter.
Conversely, the Dependent Variable is the 'receiver' that shows the effects of the independent variable's manipulation. So, in response to the question about Tae's investigation, the correct answer would be IV is the time spent on social media on the phone, and DV is anxiety levels, meaning the time spent on social media is the variable that Tae is manipulating to observe any subsequent changes in anxiety levels.