Compound B has molecular formula C9H10. The IR spectrum is shown below. The 1H-NMR spectrum shows a multiple at 7.2 ppm integrating to 4H, a triplet at 2.9 ppm integrating to 4H, and a triplet at 2.1 ppm integrating to 2 H. Suggest a structure for B and explain your reasoning

 

100 4000 3508 3000 25a9 2000 1580 1000 T*690 2945.68 2845.37 1463.45- 1460.30 1311.76 1265. 48 LT'6T21 1024.33