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

Options

A. (+)lactose, `C_(12)H_(22)O_(11)` contains 8-OH groups
B. on hydrolysis (+) lactose give equal amount of D(+) glucose and D(+) galactose
C. (+) Lactose is a `beta`-glycoside formed by the union of a D(+) glucose and a molecules of D(+) galactose
D. (+) lactose is reducing sugar and does not exhibit mutarotation

Explanation

To determine which statement is not true regarding (+) lactose, we will analyze each statement step by step.

### Step 1: Understand the Structure of Lactose
Lactose is a disaccharide sugar composed of two monosaccharides: D-glucose and D-galactose. It has a specific structure that includes multiple hydroxyl (OH) groups.

### Step 2: Analyze Each Statement

1. **Statement 1**: "The (+) lactose contains 8 OH groups."
- **Analysis**: Upon examining the structure of lactose, it indeed contains 8 hydroxyl groups. This statement is true.

2. **Statement 2**: "On hydrolysis, (+) lactose gives equal amounts of D-glucose and D-galactose."
- **Analysis**: Hydrolysis of lactose yields one molecule of D-glucose and one molecule of D-galactose in equal amounts. This statement is also true.

3. **Statement 3**: "Lactose is a beta-glucoside formed by the union of a D-glucose and a molecule of D-galactose."
- **Analysis**: This statement is correct as lactose is formed by a glycosidic bond between D-glucose and D-galactose, specifically a beta linkage. This statement is true.

4. **Statement 4**: "Lactose is a reducing sugar and does not show mutarotation."
- **Analysis**: Lactose is indeed a reducing sugar and it does show mutarotation due to the presence of a free aldehyde group in its structure. Therefore, this statement is false.

### Conclusion
The statement that is not true regarding (+) lactose is: **"Lactose is a reducing sugar and does not show mutarotation."**