Question: What remembrance day held on April 25 features a riderless horse leading the march?
Sentence (from "Anzac Day"): Anzac Day is a national day of remembrance in Australia and New Zealand that broadly commemorates all Australians and New Zealanders "who served and died in all wars, conflicts, and peacekeeping operations" and "the contribution and suffering of all those who have served".
Relevant evidence: No