When a monosaccharide forms a cyclic hemiacetal, the carbon atom that contained the carbonyl group is identified as the .... Carbon atom, because

• A

  D, the carbonyl group is drawn to the right
• B

  L, the carbonyl group is drawn to the left
• C

  acetal,it forms bond to an $-\mathrm{OR}$ and an $\mathrm{OR}^{\prime}$
• Correct answer
  D

  anomeric, its substituents can assume an $\beta$ or $\alpha$ position

Solution

When two cyclic forms of a carbohydrate differ in configuration only at hemiacetal carbons, they are said to be anomers. Thus, anomers are cyclic forms of carbohydrates that are epimeric at hemiacetal carbon and this carbon ( $\mathrm{C}-1$ of aldose) is called anomeric carbon, e.g.,

Hence, the correct answer is option: 'D'.