Which iconic landmark is associated with the summer ceremony Trooping of the Colour?

The Trooping of the Colour is an annual event that marks the official birthday of the British sovereign and is closely associated with Buckingham Palace. During this ceremony, members of the royal family, including the Queen or King, usually appear on the balcony of Buckingham Palace to watch the parade and military display. The event features a variety of regiments of the British Army performing ceremonial duties, showcasing the pageantry and tradition that is integral to the British monarchy. While the other landmarks listed have their own historical significance, none are directly linked to the specific ceremonial activities of the Trooping of the Colour. Buckingham Palace serves as the royal residence where these celebrations are observed, making it the most fitting choice in this context.