The question asks: Positive Tollen’s test is observed for. However, the actual compounds corresponding to options A, B, C, D are missing in the prompt.

1. Principle of Tollen’s test

Tollen’s reagent is ammoniacal silver nitrate, which oxidizes suitable compounds and gives a silver mirror or black precipitate of silver.

A positive Tollen’s test is generally shown by:

1. Aldehydes
2. Formic acid and compounds that can be oxidized similarly
3. $
   -hydroxy ketones (via enediol formation in basic medium)
4. Some reducing sugars

Ordinary ketones usually do not give Tollen’s test.

2. Limitation here

Since the structures/options are not provided, it is not possible to independently verify whether options A, B, C are indeed the correct set.

3. Comparison with stored answer

The stored correct answer is A, B, C, but without seeing the actual option contents, I cannot rigorously derive or confirm that selection from chemistry principles applied to the given choices.

Therefore, I must mark that I cannot verify agreement confidently from the incomplete data.