Read the passage given below and answer the following questions :
According to Valence Bond Theory, the metal atom or ion under the influence of ligands can use its (n-1)d, ns, np or ns, np, nd orbitals for hybridisation to yield a set of equivalent orbitals of definite geometry such as octahedral, tetrahedral, square planar and so on. These hybridised orbitals ar allowed to overlap with ligand rbitals that can donate electron pairs for bonding.
Assertion (A) : In the diamagnetic octahedral complex, `[Co(NH_(3))_(6)]^(3+)`, the cobalt ion is in +3 oxidation state.
Reason (R) : Six pairs of electrons, one from each `NH_(3)` molecule, occupy the six hybrid orbitals.

Options

A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
B. Assertion and reason both are correct statements and reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement
D. Assertion is wrong statements but reason is correct statement.

Explanation

To solve the question, we need to analyze the assertion (A) and the reason (R) provided in the context of the passage about coordination compounds and Valence Bond Theory.

### Step 1: Analyze the Assertion (A)
The assertion states that in the diamagnetic octahedral complex \([Co(NH_3)_6]^{3+}\), the cobalt ion is in the +3 oxidation state.

1. **Determine the oxidation state of cobalt**:
- The ligand \(NH_3\) is a neutral ligand, meaning it does not contribute any charge.
- Let the oxidation state of cobalt be \(x\).
- The overall charge of the complex is +3.
- Therefore, we can set up the equation:
\[ x + 6(0) = +3 \implies x = +3 \]
- Thus, the assertion is **true**.

### Step 2: Analyze the Reason (R)
The reason states that six pairs of electrons, one from each \(NH_3\) molecule, occupy the six hybrid orbitals.

1. **Understanding the hybridization**:
- In an octahedral complex, the central metal ion (cobalt in this case) undergoes hybridization to form six equivalent orbitals.
- For \(Co^{3+}\), the electronic configuration is \( [Ar] 3d^6 \).
- When \(Co^{3+}\) forms an octahedral complex with six \(NH_3\) ligands, it uses \(d\), \(s\), and \(p\) orbitals for hybridization.
- The hybridization involved is \(d^2sp^3\) (two \(d\) orbitals, one \(s\) orbital, and three \(p\) orbitals).
- Each \(NH_3\) donates a pair of electrons to form coordinate bonds with the cobalt ion.

2. **Confirming the reason**:
- The statement that six pairs of electrons occupy the six hybrid orbitals is **true**.

### Step 3: Conclusion
Both the assertion (A) and the reason (R) are true. However, the reason does not provide a direct explanation for the assertion. The assertion is about the oxidation state of cobalt, while the reason discusses the electron pairing and hybridization without linking it back to the assertion about the oxidation state.

### Final Answer
- **Assertion (A)**: True
- **Reason (R)**: True
- **Conclusion**: The assertion is correct, and the reason is correct but does not explain the assertion. Therefore, the correct answer is that both are true, but the reason is not the correct explanation for the assertion.

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