Answer: d) People don't always know their own thought processes.
Explanation: Cognitive psychologist usually tend to ask people about the thinking process the persist while conducting a research.This helps in people focusing on their mental ability and health that is displayed through their thoughts. Selecting this method for research is usually done because people are mostly not aware about their thought process and mind.
Other options are incorrect because it is not a easier method neither damage the laws . Psychologist do not only focus on preverbal children.Thus, the correct option is option(d).
