To achieve the result "I solved this quiz!" in cell B2, we need to use the SUBSTITUTE function. The SUBSTITUTE function replaces existing text with new text within a string. Its syntax is SUBSTITUTE(text, old_text, new_text, [instance_num]). Based on the spreadsheet data: The original text is in cell A2: "I will solve this quiz!" The text to be replaced (old_text) is in cell B4: "will solve" The replacement text (new_text) is in cell B5: "solved" Therefore, the core of the formula should be SUBSTITUTE(A2, B4, B5). The dollar signs ($) indicate absolute references, which are valid as long as they point to the correct cells. Let's evaluate each option: =SUBSTITUTE(A2,B5,B4): This formula attempts to replace the content of B5 ("solved") with the content of B4 ("will solve") in A2. Since "solved" is not in A2, this will not produce the desired result. =SUBSTITUTE(A2,B4,B5): This formula correctly replaces the content of B4 ("will solve") with the content of B5 ("solved") in A2. This will result in "I solved this quiz!". =SUBSTITUTE($A2,$B4,$B5): This formula also correctly replaces the content of B4 ("will solve") with the content of B5 ("solved") in A2. The absolute references ($) do not change the result for this specific cell. =SUBSTITUTE($A2,B5,B4): Similar to the first option, this attempts to replace "solved" with "will solve" in A2, which is incorrect. =SUBSTITUTE(A2,$B4,$B5): This formula correctly replaces the content of B4 ("will solve") with the content of B5 ("solved") in A2. The absolute references for B4 and B5 are valid. =SUBSTITUTE(A2,$B$4,$B$5): This formula correctly replaces the content of B4 ("will solve") with the content of B5 ("solved") in A2. The absolute references for B4 and B5 are valid. The valid formulas are: =SUBSTITUTE(A2,B4,B5) =SUBSTITUTE($A2,$B4,$B5) =SUBSTITUTE(A2,$B4,$B5) =SUBSTITUTE(A2,$B$4,$B$5) 3 done, 2 left today. You're making progress.