Answer:
<em>The correct option is B) number of patients with brain tumors</em>
Explanation:
In a scientific experiment, an independent variable is a variable which is being changed by the scientist or changes naturally. The effect of the independent variable is studied on another variable which is termed as the dependent variable. Hence, the dependent variable can be described as the variable which is under study in a scientific experiment.
In the following scenario, as the effect of prolonged cell phones is being tested on causing brain tumors hence, the number of patients with brain tumors will be the dependent variable.
The answer is D
Hope this help
