(16 points) A compound with molecular formula C;H,„O; has the proton nmr spectrum below (integrations are shown next to multiplets) and prominent IR frequencies at 2979 and 1735 cm'.One of

the 20 structures below is the correct one. Circle it and assign the nmr spectrum (i.., show the correspondence between nmr peaks and protons in the molecule). All spin-spin coupling constants are the same.