To determine how paragraph 9 contributes to the reader's understanding of dark matter, you would need to analyze the content of that specific paragraph. However, based on the options provided:
A. It highlights how mysterious dark matter is.
B. It lists the elements known to be in dark matter.
C. It prompts readers to guess what dark matter is made of.
D. It suggests that scientists will never know what dark matter is.
The answer that best reflects the common narratives found in discussions about dark matter is likely A. It highlights how mysterious dark matter is. This aligns with the general context surrounding dark matter, which emphasizes its elusive nature and the ongoing scientific exploration to understand it better.
If you have the specific paragraph's text, I could provide a more accurate assessment.