One molecule of glucose and one molecule of galactose form:
(a) Lactose
(b) Maltose
(c) Sucrose
(d) Inulin

Options

A. Lactose
B. Maltose
C. Sucrose
D. Inulin

Answer

To solve the question, we need to identify which disaccharide is formed when one molecule of glucose combines with one molecule of galactose.

### Step-by-Step Solution:

1. **Understanding the Components**:
- We have two monosaccharides: glucose and galactose.
- Both of these are simple sugars.

2. **Identifying the Disaccharide**:
- Disaccharides are formed when two monosaccharides combine through a glycosidic bond.
- The question specifically asks what is formed when glucose and galactose combine.

3. **Recognizing the Correct Disaccharide**:
- When glucose (C6H12O6) and galactose (C6H12O6) combine, they form lactose (C12H22O11) through a condensation reaction, which releases a water molecule.
- The reaction can be summarized as:
\[ \text{Glucose} + \text{Galactose} \rightarrow \text{Lactose} + \text{H}_2\text{O} \]

4. **Evaluating Other Options**:
- **Maltose**: This disaccharide is formed from two glucose molecules. Therefore, it is not the correct answer.
- **Sucrose**: This disaccharide is formed from one glucose and one fructose molecule. Hence, it is also not the correct answer.
- **Inulin**: This is a polysaccharide made up of fructose units, and thus it is not relevant to the combination of glucose and galactose.

5. **Conclusion**:
- The only correct answer is **(a) Lactose**.

### Final Answer:
(a) Lactose