One example of the cultural advancements made during the gupta empire is
a. classification of one thousand new diseases.
b. development of an early form of chess.
c. introduction of the number zero.
d. use of a new calendar system.

The correct answer is letter D. The introduction of the number zero was a part of the Gupta Empire. Due to this a lot of scholars during that period also postulated the theory that the Sun is the center of the solar system and that the Earth and other planets revolve around it. 

The Gupta Empire was known to be the Golden Age of India because of great leaps made in science, arts, mathematics, and literature.