Phenol $\xrightarrow[\text { (ii) } \mathrm{CO}_2 / 140^{\circ} \mathrm{C}]{\text { (i) } \mathrm{NaOH}} A \xrightarrow{\mathrm{H}^{+} / \mathrm{H}_2 \mathrm{O}}$ $B \xrightarrow{\mathrm{Ac}_2 \mathrm{O}} C$
In the above reaction, end product ‘C’ is