which is sweet in taste,
but is not sugar ?
starch
saccharine
Lactose
protein

Options

A. starch
B. saccharide
C. Lactose
D. protein

Answer

To solve the question "Which is sweet in taste, but is not sugar?" we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a substance that is sweet in taste but is not classified as sugar.

2. **Analyzing the Options**:
- **Starch**:
- Starch is a carbohydrate but is not sweet in taste. It is a polymer of glucose and is typically tasteless. Therefore, it does not fit the criteria of being sweet.
- **Saccharin**:
- Saccharin is an artificial sweetener. It is not a sugar but is known for its sweet taste. This option meets both criteria: it is sweet and not a sugar.
- **Lactose**:
- Lactose is a sugar (specifically, it is known as milk sugar) and it tastes sweet. Therefore, it does not meet the requirement of not being a sugar.
- **Protein**:
- Proteins are made of amino acids and are generally tasteless. They do not have a sweet taste, so they do not fit the criteria.

3. **Conclusion**: After analyzing all the options, the only substance that is sweet in taste but is not classified as sugar is **saccharin**.

### Final Answer:
**Saccharin**

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