Concept:Bandi Chhor Divas is a Sikh festival that celebrates the release of Guru Hargobind Sahib from imprisonment.Key Fact:In 1619, Guru Hargobind was freed from Gwalior Fort along with 52 captive kings.Explanation:Guru Hargobind insisted that all 52 kings be released with him. He wore a special robe with 52 strings so each king could hold one and walk out. This day falls near Diwali and is marked by lighting lamps, prayers, and langar. Option A is correct because it commemorates this event. Option B is wrong: Guru Arjan Dev's martyrdom is observed on Shaheedi Divas. Option C is wrong: Sikh festivals do not involve fasting or silence. Option D is wrong: Bandi Chhor Divas is celebrated worldwide, not only at the Golden Temple, and includes processions.Answer:A. Commemorates Guru Hargobind's release with 52 kings.