It seems to me that the answer is D
"Gordian" is an adjective pertaining to the ancient king of Phrygia, Gordius. This king tied a knot that can only be undone by the person who was the right fit to rule Asia.
As you can see, this adjective refers to something rather difficult and sophisticated.
Therefore, synonyms for this adjective would be: sophisticated, complicated, obscure or convoluted.
Answer:
small animals are smarter than larger animals
An aurora, white and colored lights, are located in the polar regions.
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