Which additional word in the sentence should be capitalized?

The tango, an argentine dance for couples, became popular in 1910.

A.

Argentine

B.

Dance

C.

Popular

D.

Couples

The word that should be capitalized in this sentence is Argentine.

Why?

The other options (dance, popular, and couples) are all normal words that are likely used every day. Argentine is a word that describes the citizens of Argentina. Argentine is a proper noun, so it should be capitalized. Just like the food Swiss cheese, Swiss is capitalized because it describes the citizens of Switzerland.

I think it's

A.

Argentine