[camilafonseca]

In this question, I'm uncertain whether my answer is correct or not. The issue is that I'm not quite sure about what promotes acidity the most: two Cl in an atom which is four bonds away from COOH (in my class, the teacher mentioned the maximum distance for an effective inductive effect is three bonds) or a Cl which is directly connected to COOH.

The molecules used in the exercise were the four present in the last row of this image:
https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Exercises%3A_Organic_Chemistry/Organic%3A_Acid%2F%2FBase_Practice_Problems/Solution_32

What I was able to identify is that "compound 1" (last row) is the least acidic and "compound 4" (also last row) is the most acidic, but could be sure what criteria to use for compounds 2 and 3. I thought the order could be 1<3<2<4, considering that a single Cl directly  attached to COOH would outweight (regarding its contribution to acidity) two Cl connected in a carbon which is three bonds away from the carbonyl. Does that make sense?

[incorporealist]

You are correct. The two Cl multiple bonds away from the carboxyl group have no electron withdrawing effects, while the single Cl one bond away does.