In the following reaction, identify A and B :
`underset(C)underset(" "darr "Conc. nitric acid")(C_(6)H_(12)O_(6))overset("Acetic anhydride")(rarr) A`

Options

A. `A = COOH-(CH_(2))_(4)-COOH, B = OHC-(CHOCOCH_(3))_(4)-CH_(2)OCOCH_(3)`
B. `A = COOH-(CH_(2))_(4)-CHO, B = OHC-(CHOCOCH_(3))_(4)-CH_(2)OCOCH_(3)`
C. `A = OHC-(CHOCOCH_(3))_(3)-CH_(2)OCOCH_(3), B = COOH-(CH_(2))_(4) - CHO`
D. `A = OHC-(CHOCOCH_(3))_(4)-CH_(2)OCOCH_(3), B = COOH-(CH_(2))_(4) - COOH`

Explanation

To solve the problem, we need to identify the compounds A and B in the given chemical reaction involving glucose (C₆H₁₂O₆) in the presence of concentrated nitric acid (HNO₃) and acetic anhydride.

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactant is glucose, which has the molecular formula C₆H₁₂O₆.

2. **Understand the Role of Concentrated Nitric Acid**:
Concentrated nitric acid (HNO₃) is a strong oxidizing agent. When glucose is treated with concentrated nitric acid, it undergoes oxidation.

3. **Determine the Oxidation Products**:
The oxidation of glucose by concentrated nitric acid typically leads to the formation of saccharic acid (also known as glucaric acid). The reaction can be summarized as:
\[ C_6H_{12}O_6 \xrightarrow{HNO_3} C_6H_{10}O_8 \]
Here, saccharic acid (C₆H₈O₆) is formed.

4. **Identify Compound A**:
In this context, compound A is saccharic acid (C₆H₈O₆).

5. **Consider the Role of Acetic Anhydride**:
Acetic anhydride is often used in organic chemistry to acetylate compounds. However, in this specific reaction, it is not necessary for the oxidation of glucose, but it may be used in further reactions to modify the product.

6. **Identify Compound B**:
Since the question does not provide further reactions involving acetic anhydride, we can conclude that compound B is not specified in the context of this reaction.

### Final Answer:
- **A**: Saccharic Acid (C₆H₈O₆)
- **B**: Not specified in the context of this reaction.