A compound X (C10H14O) dissolves in aqueous sodium hydroxide but is insoluble in aqueous sodium bicarbonate. Compound X reacts with bromine in water to yield a dibromo derivative, C10H12Br2O. The 3000-4000-cm-1 region of the IR spectrum of X shows a broad peak centered at 3250 cm-1; the 680-840-cm-1 region shows a strong peak at 830-cm-1. The 1H NMR spectrum of X gives the following: singlet at d 1.3 (9H), singlet at d 4.9 (1H), and multiplet at d 7.0 (4H). What is the structure of X?