The correct answer is D. It is a very strong and very specific research question.
Step-by-step explanation
When conducting an investigation, it is necessary to ask an appropriate question to adequately develop the research. To construct a suitable question it is necessary to select a specific topic so as not to cover too much information and to avoid digression. On the other hand, a correct question for an investigation must be open to being able to adequately deepen the subject and cover the subjects necessary to test our hypothesis. These features allow our question to be suitable, giving strength to the investigation and specificity. So the answer is D. because the question ".How did colonialism impact modern society?" establishes a specific topic "colonialism and modern society" and it is an open-ended question as it starts with the word "how" and there can be different possible answers.