Answer:
The correct answer will be- size of the parachute.
Step-by-step explanation:
A scientific experiment is performed to test the hypothesis if it could be proved or not.
An experiment must include all the variables mentioned in the hypothesis which can be categorized as the variable which can be manipulated called the independent variable and the variable which has to be tested called the dependent variable.
In the given question, the variable to be tested (dependent variable) is the time required by the parachute to fall on the ground and the variable which could be manipulated (independent variable) will be the size of the parachute in the experiment.
Thus, the size of the parachute is the correct answer.