Which of these is the basis for some traditional calendars? A-cycles of the moon
B-constellations in the heavens
C-solar and lunar eclipses
D-the appearance of seasonal rainstorms

A-cycles of the moon

Explanation:

The people of Ancient Greece, Rome and China counted their year based on a 12 moon cycle ( that is, about 354 days). A 13th cycle of the moon is included so that the lunar year remains in step with the seasons of the year.

Today, the Gregorian calendar is mostly used around the world. This calendar was

actually adapted from an earlier lunar version. Ancient civilizations used the phases of the moon to help identify the seasons.

The major difference between the lunar calendar and the solar calendar is the kind of celestial body that is used to determine time.