Answer: D. Luxembourg's coat of arms
Step-by-step explanation: Following the Napoleonic Wars, Luxembourg, which had been part of the Holy Roman Empire, became a separate country under the protection of the Netherlands. Its national colors, derived from the ducal coat of arms, came to be used as a horizontal red-white-blue tricolor, adopted on June 12, 1845.
The Duchy of Limburg, located in present-day Belgium and the Netherlands, is where the origins of Luxembourg's coat of arms may be found. The arms are designated as Barry of ten Argent and Azure, a Lion rampant queue forchée Gules crowned, armed and langued Or in heraldic terminology.