Final answer:
Authority, a priori, and science are methods used in the field of Social Studies. Authority refers to accepted knowledge based on the source, a priori knowledge is gained through reasoning, and science is a systematic study using observation and experimentation.
Step-by-step explanation:
Authority, a priori, and science are methods used in the field of Social Studies. Authority refers to information or knowledge that is accepted as true based on the source or person providing it. A priori knowledge is knowledge that is gained through reasoning and deduction, independent of empirical evidence. Science, on the other hand, is a systematic study that uses observation, experimentation, and the scientific method to gather knowledge and understand the world.