Translation:Jij hebt helemaal niks ontdekt!
"U hebt overal niets ontedekt" was a wrong alternative - what does "overal" mean?
Overal means everywhere in the majority of Dutch sentences. For example: Ik heb overal gekeken = I have looked everywhere, or Wij zochten overal = We searched everywhere. The English word overall doesn't have the same meaning as the Dutch overal.
I see, thank you very much!