X is a compound with molecular formula $\text{C}_4\text{H}_{10}\text{O}_2$. It has a straight-chain carbon skeleton and includes two OH groups. When X reacts with an excess of hot, acidified, aqueous manganate(VII) ions, it is changed into a compound with molecular formula $\text{C}_4\text{H}_6\text{O}_4$. To which two carbon atoms in the chain of X are the two OH groups attached?
- A1st and 2nd
- B1st and 3rd
- C1st and 4th
- D2nd and 3rd