Answer:
Step-by-step explanation:
The graph is about the height of the grass thourgh time, that means Brady is analysing how long it takes to the grass to grow.
It's important to know that time is a variable which doesn't depends on any other variabel, that is, it's an independent variable all the time.
Therefore, Time is the independent variable and Height of the Grass is the dependent variable.
This is just simple deduction, because the grass grows through time, it doesn't happen in the opposite way, time doesn't change accoring to the height of the grass.