Answer:
The correct answer is D) Certain moves in the Indian Kathak dance- such as the quick turn and flip- are the same moves one finds in the Spanish Flamenco dance.
Step-by-step explanation:
This option can be considered a concrete fact because, as all facts, it can be verified by any person (contrary to a hypothesys for example, which needs to present facts to be proven correct and "existant"). Meaning, any person with eyes (or an acute sense of hearing) can verify wether the dance movements mentioned in the Kathak dance resemble or not those of the Spanish flamenco.
In the case of option C) for instance, wether historians and critics have suspected that the two dances are similar or not is an abstract assertion. There is no proof stated regarding which or how many authors have made said assertion, and thus it is considered a vague fundament.
Both, option B) and option A) are not facts that serve to support the hypothesis.