What would be the different approaches to find a right answer from the given set of options for acidic strengths in different orders?

Acidic strength is found in terms of 
1) K_a value. 
More the K_a value more will be the acidic nature
2) pK_a value
More the pK_a value less will be the acidic strength. 
3) In terms of inductive effect
More the +I groups (electron releasing groups) less will be the acidic strength
More the -I groups (electron withdrawing groups) more will be the acidic strength

4) If the conjucate bases are less in strength more will be the acidic strength.