Answer: The right answer is<em> magnum opus</em>, in singular, and <em>magna opera</em>, in plural.
Explanation: Just to elaborate a little on the answer, it can be added that <em>magnum opus</em> literally means "great work," and it is an expression used to describe a literary piece, a musical composition, a painting, a film, or other example of artistic creativity and genius that stands as the best and most important achievement of its creator.
Idk can u provide more info unless it’s a joke ...
That was Rainsford............
The countries that existed in Ancient Greece were Athens, Sparta,
Thebes, Eretria, Corinth, Chalcis and Syracuse. Most notable of these
were the countries of Athens and Sparta, because it was the armies of
these countries that fought against the Persians during the war.
