Answer:
d. Descartes; Plato.
Step-by-step explanation:
For Descartes, the mind operates under two principles: intuition and deduction. The first is the simple observation and the second implies a consecutive order of ideas that implies a conclusion. That's the way kwonledge is build.
Plato, on the other hand, considers that knowledge is something we have already met before the soul were trapped into the body. In this case is not necessary a method to reach knowledge -like Descartes proposed- all we need is to observe the nature and then remember. Thats why would be enough for Miguel to measure and investigate what happens within the mind.