Answer: D. The reigns of kings
Step-by-step explanation:
The Canon of Kings which was preserved by Claudius Ptolemy, recorded the reigns of various kings from the Babylonians to the Persians and to the Ptolemies and the Romans. The accuracy is generally not questioned by historians indicating its accuracy.
The Canon was useful to early astronomers such as Ptolemy would use it to date the lunar eclipses as well as other astronomical events to the various reigns of different kings.