C-11-Q039mediumsingle_mcqপ্রোপান্যালের সংকেত—aC2H5CHO\mathrm{C_2H_5CHO}C2H5CHObCH3CHO\mathrm{CH_3CHO}CH3CHOcCH3COOH\mathrm{CH_3COOH}CH3COOHdC2H5OH\mathrm{C_2H_5OH}C2H5OH