Ahousekeeper would most likely fall under this classification? (a: professional service, b: domestic and personal service, c: trade and transportation, or d: none of the above.)

Historians have recently discovered a historical journal published in the early twentieth century. the journal contains facts based on original sources about the downfall of the early byzantium empire. historians consider this long-lost journal to be a breakthrough in their understanding of the byzantium empire. based on this information, the journal is a source.