Answer:
C. A German priest of the 1600s, Athanasius Kircher, wrote the first grammar and vocabulary of Coptic, the language of Christian Egypt.
Step-by-step explanation:
Fact refers to any information or anything that is proven true and known, accepted as true. It is the true accounts or information given as opposed to something that is interpreted or reproduced.
In the given passage from "The Riddle of the Rosetta Stone" by James Cross Giblin, the fact statement or sentence is "[a] German priest of the 1600s, Athanasius Kircher, wrote the first grammar and vocabulary of Coptic, the language of Christian Egypt." This sentence is true and proven, and not something that the author made up. It is not something that is fictionalized, but rather a piece of true information.
Thus, the correct answer is option C.