Which one of the following statements is not true regarding $(+)$ lactose?

• A

  (+) lactose is a $\beta$-glycoside formed by the union of a molecule of $D(+)$ glucose and a molecule of $\mathrm{D}(+)$ galactose
• Correct answer
  B

  (+) lactose is a reducing sugar and does not exhibit mutarotation
• C

  (+) lactose, $\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}$ contains 8-O $\mathrm{H}$ groups
• D

  On hydrolysis (+) lactose gives equal amount of $\mathrm{D}(+)$ glucose and $\mathrm{D}(+)$ galactose

Solution

Lactose is a reducing sugar and all reducing sugars show mutarotation.

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