C 10:59 ปี 3 (15 H16.34 - Level 3 Unanswered 2 attempts left An unknown compound (A) exhibits a mass spectrum with peaks at m/z=84 (74%) and 55 (100%). The IR spectrum shows absorptions at 3050, 2950, 1649 and 1070 cm ¹. A reacts with H₂/Pt to give B, which shows a mass spectrum with peaks at m/z=86 (50%), 85 (55%), and 56 (60%). The IR spectrum of B shows absorptions at 2960 and 1093 cm ¹. Reaction of A with O3 gives a single fragment that shows a molecular ion at m/z=116. When A is incubated in methanol with a drop of H2SO4, product C is obtained, which has a mass spectrum with peaks at m/z=116 (1%), 71 (100%), and 43 (45%). What are the structures of A, B, and C? B A | = III D IV E V Submit

C 10:59 ปี 3 (15 H16.34 - Level 3 Unanswered 2 attempts left An unknown compound (A) exhibits a mass spectrum with peaks at m/z=84 (74%) and 55 (100%). The IR spectrum shows absorptions at 3050, 2950, 1649 and 1070 cm ¹. A reacts with H₂/Pt to give B, which shows a mass spectrum with peaks at m/z=86 (50%), 85 (55%), and 56 (60%). The IR spectrum of B shows absorptions at 2960 and 1093 cm ¹. Reaction of A with O3 gives a single fragment that shows a molecular ion at m/z=116. When A is incubated in methanol with a drop of H2SO4, product C is obtained, which has a mass spectrum with peaks at m/z=116 (1%), 71 (100%), and 43 (45%). What are the structures of A, B, and C? B A | = III D IV E V Submit