Use the table to answer the question. Table: Open Store-Day Sales Columns: Region; Open Stores; Operating Days; Net Sales Rows: Region: North; Open Stores: 18; Operating Days: 30; Net Sales: $540,000 Region: South; Open Stores: 15; Operating Days: 28; Net Sales: $420,000 Region: West; Open Stores: 12; Operating Days: 30; Net Sales: $396,000 Which comparison correctly gives net sales per open store-day for the South region?