The diagram illustrates the structure of ethanedioic acid. Ethanedioic acid reacts with ethanol, with a few drops of concentrated sulfuric acid present, to produce a diester. The molecular formula of the diester is $\text{C}_6\text{H}_{10}\text{O}_4$. What is the structural formula of this diester?
- A$\text{CH}_3\text{CH}_2\text{CO}_2\text{CO}_2\text{CH}_2\text{CH}_3$
- B$\text{CH}_3\text{CH}_2\text{OCOCO}_2\text{CH}_2\text{CH}_3$
- C$\text{CH}_3\text{CH}_2\text{O}_2\text{CO}_2\text{CCH}_2\text{CH}_3$
- D$\text{CH}_3\text{CO}_2\text{CH}_2\text{CH}_2\text{OCOCH}_3$