Answer: A. Albert Einstein’s early career.
Explanation: A documented essay or a research paper is a piece of writing in which you incorporate information (facts, arguments, opinions) taken from the writings of experts in a particular field. One of the most important steps to write a documented essay is to choose a good topic, it should be well defined and narrow enough to be covered in the essay. From the given options, the topic that would serve as the subject of a documented essay is "Albert Einstein’s early career" because the other ones are too extensive and general.
