Identify the countries, their capitals, and the languages spoken in the following sentences. Output in JSON format.

a) Amidst the idyllic vistas, Copenhagen, Denmark's capital, captivates visitors with its thriving art scene and the enchanting Danish language spoken by its inhabitants.
b) Within the enchanting realm of Eldoria, one discovers Avalore, a grandiose city that emanates an ethereal aura. Lumina, a melodious language, serves as the principal mode of communication within this mystical abode.
c) Nestled amidst a harmonious blend of age-old customs and contemporary wonders, Buenos Aires, the capital of Argentina, stands as a bustling metropolis. It is a vibrant hub where the expressive Spanish language holds sway over the city's inhabitants. Make sure to only use capital letters in your entire response.
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