Which of the following is/are inner orbital complex as well as paramagnetic with magnetic moment equal to 3.78 (approx) ?

Options

A. `[Co(O X)_(3)]^(3-)`
B. `[Cr(NH_(3))_(6)]^(3+)`
C. `[Fe(H_(2)O)_(5)NO]^(2+)`
D. `[Zn(NH_(3))_(6)]^(2+)`

Explanation

To determine which of the given complexes is an inner orbital complex as well as paramagnetic with a magnetic moment of approximately 3.78, we will analyze each complex step by step.

### Step 1: Identify the oxidation states and electronic configurations of the metal ions in the complexes.

1. **Cobalt (Co)**:
- Oxidation state: +3
- Electronic configuration: Co (atomic number 27) → [Ar] 3d^6.

2. **Chromium (Cr)**:
- Oxidation state: +3
- Electronic configuration: Cr (atomic number 24) → [Ar] 3d^5 4s^1 → 3d^3 in +3 state.

3. **Iron (Fe)**:
- Oxidation state: +1
- Electronic configuration: Fe (atomic number 26) → [Ar] 3d^6 4s^2 → 3d^6 4s^1 in +1 state.

4. **Zinc (Zn)**:
- Oxidation state: +2
- Electronic configuration: Zn (atomic number 30) → [Ar] 3d^10 4s^2.