Answer:
It was a breakthrough in his research.
Explanation:
According to the riddle from the excerpt from The Riddle of the Rosetta Stone, the statement that best describes the influence his colleague's act had on Jean-François Champollion is that it was a breakthrough in his research.
Based on the riddle, a copy of an inscription found in the ruins of a temple on the Nile River Island of Philae was sent by a colleague which helped his research massively as it was found on the site of his project.
