The first paragraph of the passage points out that though Kahlo's work has been extensively psychoanalyzed, her work's political content has been less studied (4-7).
The entire passage discusses how pervasive Kahlo's political beliefs were in her work, e.g. "In her paintings, Kahlo repeatedly employed Aztec symbols, such as skeletons or bleeding hearts, that were traditionally related to the emanation of life from death and light from darkness (30-33)." We are told in the passage that "Mexican nationalism--identified the Aztecs as the last independent rulers of an indigenous political unit (20-24)." Thus, it is correct to say that the main purpose of the passage is to advocate an additional interpretation to Kahlo's work, other than just psychoanalytic, i.e. answer choice (D).
The problem with answer choice (E) is that the passage never mentions "new discoveries." The passage is about the pervasive presence of Kahlo's political beliefs in her paintings, indicating that a new political approach should be taken in the interpretation of her work.
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