A naturally occurring amino acid with the formula C9H11NO3 gives the following proton NMR spectrum when determined in deuterium oxide solvent with DCl added. The amino, carboxyl, and hydroxyl protons merge into a single peak at 5.1 ppm (4 H) in D2O. Determine the struc- ture of this amino acid and explain the pattern that appears in the range 3.17 to 3.40 ppm, including coupling constants.