Concept:Arrange sentences in logical chronological order of an excavation process.Explanation:Sentence P starts with laying out the grid and digging topsoil.Sentence Q follows as it describes documenting artefacts after they are unearthed.Sentence R continues with cleaning and cataloguing the discovered items.Sentence S concludes by explaining how artefacts tell the story of a lost culture.Thus the correct order is P, Q, R, S.Answer:D. P, Q, R, S