In the spreadsheet shown below (attached), we computed profit earned by selling houses by entering the formula =F8-E8 in cell G8 and copying it down to G9:G11. We used the word open to denote a house that is not yet sold. Unfortunately, when a house has not yet been sold our spreadsheet shows the #VALUE error, because you cannot subtract the buy price from the word open. We would like to "error trap" Column G so that when a house has been sold the correct profit has been computed and if the house has not yet been sold a _ will be entered in Column G. How many of the following formulas could be entered in cell G8 and copied down to G9:G11 to achieve this goal?

? I. IFERROR(F8-E8,"_ ") ? II. ISERROR(F8-E8," _") ? III. IF(COUNT(G8)>0,F8-E8,"_") ? IV. IFERROR(F8-E8,_) ? V. IFERROR(E8-F8,"_ ")