as part of an investigation on the synthesis of various nitrogen and oxygen containing heterocycles, a series of amino alcohols were treated with aldehydes and ketones. in one of the runs a colorless liquid product was obtained. a small sample of this liquid product was sent out to a lab for combustion analysis. the results indicated that the product contained 40.67% carbon, 8.53% hydrogen, and 23.71% nitrogen. which structure is consistent with this combustion analysis data? (atomic weights: c