Read the description of René Descartes below. Which step of the scientific method does the description most closely match?

René Descartes was a French philosopher born in 1596, a time when many long held beliefs were changing. His new way of thinking led him to decide to doubt everything until he could prove it. His goal was to achieve certainty through methodical and logical questioning.
A. Step 2: Form a hypothesis.
B. Step 3: Test the hypothesis.
C. Step 4: Collect data.
D. Step 1: State the question or observation.