The correct answer is C. A Primary Source
Step-by-step explanation
A primary source is any document that contains first-hand information, it means the author of the document somehow participated in the events it is describing, while in secondary sources the author discusses, describes or summarizes the information presented in another source, which is usually a primary source. In this case, the author gathered the data from a series of specific events and is reporting the finding of it, this implies the author somehow participated in the events and as the author is not reporting another source this can be considered as a primary source.