The correct answer is B) to gather, test, and explain.
The goal of the scientific method developed by Bacon and Descartes was to gather, test, and explain.
The scientific method consists of systematic observation of phenomena, elaborate hypothesis, measurement or collecting data, making experiments to test data and finally elaborate conclusions. In order to have scientific theories or prove something that can be demonstrated, you have to use the scientific method. You test, experiment and have a determined result, once, twice, an many times. So yes, the goal of the scientific method developed by Bacon and Descartes was to gather, test, and explain.
