The $M_r$ value of compound X is 88. Compound X is warmed under reflux with excess acidified potassium dichromate(VI) to form compound Y. Under suitable conditions, compound Y reacts with compound X to give compound Z. The $M_r$ value of compound Z is 172. Identify compound X.
- A$\text{CH}_3\text{CH}_2\text{CHOHCH}_2\text{CH}_3$
- B$\text{(CH}_3)_2\text{COHCH}_2\text{CH}_3$
- C$\text{(CH}_3)_2\text{CHCHOHCH}_3$
- D$\text{(CH}_3)_3\text{CCH}_2\text{OH}$