Thanks for the reply. Yes, this would work as a function for cell C1.
What I need is a function that I can apply to the entire C column so I
just have to write one function. In other words, I don't want to write
this function in column C for every row that I have data. Is this
possible? In pseudocode, I am hoping I can create a function like:

IF(CurrentRowCell -1 CurrentRowCell - 2, "Yes", "")

and somehow assign this to the column. If this is possible, I might
need more robust code to deal with rows that don't have any data in
column A and/or column C.