To calculate the cumulative sales quantity for each brand, as shown below, what formula should be entered in cell H6 so that it can be copied across and down the table? Note: Cumulative Sales quantity at a given date includes the sum of the quantities sold from the start of the time horizon (5/1/2023) up until the given date. =SUM($B$6:B6)=SUM($B6:B6)=SUM(B6:B7)=SUM(B6:B6)=SUM(B$6:B6)