Answer:
To distinguish between an aldose and a ketone, we can use the following reagents:
(I) Br2 water
(II) Tollens reagent
(III) Fehling's solution

Explanation:
Br2 water:
Br2 water can be used to differentiate between an aldose and a ketone. Aldoses contain free aldehyde functional groups, while ketones contain a carbonyl group. When treated with Br2 water, aldoses are oxidized to carboxylic acids, and a brown precipitate of 2,4,6-tribromoanisole is formed. Ketones, on the other hand, do not react with Br2 water. Therefore, by observing the presence or absence of a brown precipitate, we can distinguish between an aldose and a ketone.

Tollens reagent:
Tollens reagent is a mild oxidizing agent that can be used to distinguish between an aldose and a ketone. It consists of a solution of silver nitrate (AgNO3) in aqueous ammonia (NH3). Aldoses can be oxidized by Tollens reagent to form carboxylic acids, while ketones do not react. When an aldose is present, Tollens reagent is reduced to metallic silver, forming a silver mirror on the inner surface of the test tube. Ketones, on the other hand, do not react with Tollens reagent and do not produce a silver mirror.

Fehling's solution:
Fehling's solution is another oxidizing agent that can be used to differentiate between an aldose and a ketone. It consists of a mixture of copper(II) sulfate (CuSO4) and sodium hydroxide (NaOH). Aldoses can be oxidized by Fehling's solution to form carboxylic acids, while ketones do not react. When an aldose is present, Fehling's solution is reduced, resulting in the formation of a brick-red precipitate of copper(I) oxide (Cu2O). Ketones, on the other hand, do not react with Fehling's solution and do not produce a precipitate.

Conclusion:
In conclusion, to distinguish between an aldose and a ketone, we can use Br2 water, Tollens reagent, and Fehling's solution. However, the only reagent that can be used exclusively for this purpose is Br2 water (option B). Tollens reagent and Fehling's solution can also be used, but they can also react with other compounds, making the interpretation of the results more complex.