The author poses a question in paragraph 5, which he then answers in paragraph 6. What purpose does this rhetorical question serve?

A It creates a direct relationship between the writer and the reader.

B It entertains the reader with some miscellaneous fun facts.

C It introduces some needed background information to the reader.

D It suggests that the reader already knows the answer.

4 The remaining objects, which are significantly smaller, are mostly either rocky bodies in the asteroid belt
between Mars and Jupiter or icy bodies in the Kuiper Belt in the distant regions beyond Neptune. Of the more than
1,000 known objects in the Kuiper Belt, 2003 UB313 and Pluto are the largest and second largest.
5 So why is there any debate at all, if the scientific view is so clear?
6 It all dates back to the discovery of Pluto in 1930. At the time, Pluto was thought to be considerably larger than
it is now known to be, and the existence of the rest of the Kuiper Belt was unknown. No other reasonable category
existed in which to place the object, so Pluto became the oddball planet at the edge of the solar system.