Please I need help with these NMR problems and explanations and how u got the answer.

50/1 point Which one structure is consistent with the proton-decoupled 13CNMR spectrum below? Correct Answer: Draw the expected structure of the compound from the 1H NMR and 13C NMR shown: C6H12O213CNMR MF C4H8O2 shows the 1H NMR signals: I 9.9ppm,1H,t(J=3Hz) II 2.5ppm,2H,t,d(J=7Hz,3Hz) III 1.4ppm,2H, sextet (J=7Hz) IV 1.1ppm,3H,t(J=7Hz) Draw the structure of the compound