Positive Tollen's test is observed for

Options

A.
B.
C.
D.

Explanation

To solve the question regarding which compounds give a positive Tollen's test, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Tollen's Test**:
Tollen's test is a chemical test used to identify aldehydes and certain ketones. It involves the reaction of the compound with Tollen's reagent, which contains silver ions (Ag+). A positive result is indicated by the formation of a silver mirror on the test tube.

2. **Identifying Compounds that Give Positive Tollen's Test**:
- **Aldehydes**: Compounds with the functional group -CHO (carbonyl group at the end of the carbon chain) will give a positive Tollen's test.
- **Alpha Hydroxy Ketones**: These are ketones that have a hydroxyl group (-OH) adjacent to the carbonyl group (C=O). They can also give a positive Tollen's test due to their ability to be oxidized.

3. **Analyzing the Given Options**:
- Check each option to see if it contains an aldehyde or an alpha hydroxy ketone.
- For example, if an option contains a structure with a -CHO group, it will give a positive Tollen's test.
- If an option contains a structure with a hydroxyl group adjacent to a carbonyl group, it will also give a positive Tollen's test.

4. **Conclusion**:
After analyzing the options, we conclude that the compounds that contain either an aldehyde group or an alpha hydroxy ketone will give a positive Tollen's test.

### Final Answer:
The correct answer is the options that contain aldehydes or alpha hydroxy ketones.

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