While reading an essay, Tyson comes across the following sentence in quotation marks. "The large size and the blue color [the Hope diamond] make it a rarity among gemstones."
Why are the words " the Hope diamond" in brackets?

A) to show that the words are not part of the original quote
B) to point out how large and colorful the diamond is
C) to indicate that the author has misspelled the gem's name
D) to emphasize the importance of the Hope Diamond