Answer : (C) Assertion is true, but Reason is false

Step 1 — Test the Assertion

Fructose is a reducing sugar, even though it is a ketose rather than an aldose. The assertion is true.

Step 2 — Test the Reason

The reason claims fructose does not reduce Fehling's solution and Tollens' reagent. This is wrong — it reduces both, giving a red-brown precipitate of $Cu_2O$ with Fehling's solution and a silver mirror with Tollens' reagent.

The reason is false.

Step 3 — Explain why a ketose still reduces these reagents

Fehling's solution and Tollens' reagent are alkaline. In alkaline medium fructose undergoes tautomerisation (isomerisation through an enediol) into glucose and mannose, both of which are aldoses :

$$\text{Fructose (ketose)} \xrightarrow[\text{enediol}]{OH^-} \text{Glucose + Mannose (aldoses)}$$

The free $-CHO$ group thus generated is then oxidised, so a positive test is observed.

Step 4 — Conclude

Assertion true, Reason false $\Rightarrow$ option (C).

General rule : all monosaccharides, whether aldoses or ketoses, are reducing sugars.