Final answer:
The biography 'Mr. Playboy' is about Hugh Hefner, not related to the provided options of Thomas Edison, Howard Hughes, Walt Disney, or Albert Einstein.
Step-by-step explanation:
The biography titled "Mr. Playboy: Hugh Hefner and the American Dream" is about Hugh Hefner, the founder of Playboy magazine. Answering the student's question, the person referred to in the incomplete sentence is none of the listed options (a) Thomas Edison, (b) Howard Hughes, (c) Walt Disney, or (d) Albert Einstein. Instead, the biography's subject is Hugh Hefner, who was an influential figure in American media and lifestyle culture, known for his role in the sexual revolution and his luxurious and controversial lifestyle.