When an organic compound of molecular formula \( C_4H_8O_2 \) undergoes hydrolysis with dilute \( H_2SO_4 \), a carboxylic acid A and an alcohol B are obtained. On oxidising B with chromic acid, carboxylic acid A is obtained. On heating A with \( P_2O_5 \), acid anhydride C of this acid is obtained. On hydrolysing this anhydride, acid A is obtained again. Identify A, B, and C and also write chemical equations related to them.