Answer:
A. American Psychological Association
Explanation:
The American Psychological Association began publishing guidelines for writing and references citation in early 20th century. Their latest edition, the sixth, was released in 2009.
These guidelines were developed to enhance the standardization of the references types and to improve the quality of communication, especially in science.
It's a structure guide used by a large number of scientific publications, both books and magazines, and in the academic world.
