Which of the Following Statements Best Characterizes Wundt's Approach to Methodology

Which of the following statements best characterizes Wundt's approach to methodology?

A) he relied exclusively on introspection
B) he relied largely on naturalistic observation
C) most of his laboratory studies employed a rigorous form of introspection, but he recognized other methods such as naturalistic observation, historical methods, etc.
D) he relied exclusively on the phenomenological method