**Core Concept**
The question is testing the student's knowledge of specific tests for identifying ketohexoses, a type of carbohydrate molecule. Ketohexoses are characterized by the presence of an aldehyde group at the end of the molecule, which can be oxidized to form ketones.

**Why the Correct Answer is Right**
The correct answer is based on the Benedict's test, which is a specific test for identifying ketohexoses. The test involves heating the sample with Benedict's reagent, a solution of copper(II) sulfate, sodium carbonate, and sodium citrate. The aldehyde group in the ketohexose molecule is oxidized to form a ketone, which then reacts with the copper(II) ions in the reagent to form a brick-red precipitate of copper(I) oxide. This is a characteristic color change that indicates the presence of a ketohexose.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because the Fehling's test is specific for reducing sugars, not ketohexoses. While ketohexoses can be oxidized, the Fehling's test does not detect ketones.
* **Option B:** This option is incorrect because the Molisch's test is a general test for carbohydrates, but it does not specifically detect ketohexoses.
* **Option C:** This option is incorrect because the Seliwanoff's test is specific for fructose, a ketohexose, but it involves a different reagent and reaction mechanism than the Benedict's test.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the Benedict's test is specific for ketohexoses, whereas the Fehling's test is specific for reducing sugars. This distinction is crucial in clinical settings where identifying the type of carbohydrate molecule is critical for diagnosis and treatment.

**Correct Answer:** B.