Anna is conducting an experiment to determine how weather affects cell phone reception. she is trying to decide the best way to conduct her experiment in order to collect meaningful data. which of the following experiments would anna collect the best data? a. test different cell phones in different locations on days with clear weather. b. test different cell phones in different locations on days with rainy weather. c. test a cell phone's reception in one location with clear weather and in another location with rainy weather. d. test a cell phone's reception in the exact same location under various atmospheric conditions.

D. Test a cell phone's reception in the exact same location under various atmospheric conditions

Explanation:

Components of an experiment:

Independent variable:

A manipulated variable, in an experiment or study, whose presence or degree incurs a change in the  dependent variable.

Dependent variable:

A variable which is being studied in the experiment and is supposed to change with respect to the independent variable.

Control variable:

Control variable includes the variables which are of no concern in the experiment and must be constant so that they do not interfere with the results of the experiment. Change in control variable might affect the results of an experiment.

In Anna's experiment, the independent variable is the atmospheric conditions. The dependent variable is cell phone reception that will change according to the atmospheric conditions. All other things related to the experiment are control variables like cellphone, location of the cell phone. Both of these must stay constant to collect the best data.

Hence, the best option is D.