TLC plate and Rf values
Tl;DR - You do not have enough information.


I cannot help but think that this question is not answerable. You have four samples: Huy Fong Sriracha and three "knock-offs". There are six lanes on the plate. All six samples contain potassium sorbate.

If the question was something more like: You have five mysterious hot sauces and one of them is Sriracha... Then the TLC plate makes sense. One of those poorly labeled lanes is sriracha and the others are the mystery sauces. You just need to pick the one that gives the same pattern of spots with the same Rf values.

You don't have that. You have a mismatch between number of lanes and number of samples. You don't know which one is the authentic standard. All of the sauces contain the potassium sorbate (and they should - its a common preservative). You've determined the Rf values and that is all you can do. Well, maybe not all. 
I can tell that lane 1 and lane 4 probably contain the same sauce and likewise lanes 2 and 5. Other than that, Jan's comment is correct. The potassium sorbate should always be at the same Rf (and since it is ionic, that likely means at the bottom of the TLC plate).