Who first asserted that scientists should conduct repeated observations and practical experiments to answer specific question?

A. Isaac Newton

B. Rene Descartes

C. Johannes Gutenberg

D. Francis Bacon

The correct answer is "D".

Francis Bacon is an English philosopher who is well known for having developed the Scientific Method. An empirical method based on the development of a hypothesis that was meant to be tested in order to prove if they were right or wrong. This practice was done under rigorous skepticism. Were the tester would try by all means to question every aspect of the hypothesis in order to test its validity. If the hypothesis passed this process, then it would become a fact.