Which of the following represent the correct sequence of indicated property ? .

Options

A. `a.Mn^(2+)ltNi^(2+)ltCo^(2+)ltFe^(2+)`: magnetic moment
B. `b.FeOgtCoOgtNiO`:basic character
C. `c.ScltTiltCrltMn`: number of oxidation states
D. `d.1.73mu:` one unpaired electrons

Explanation

To solve the question regarding the correct sequence of indicated properties among the given options, we will analyze each property step by step.

### Step-by-Step Solution:

1. **Magnetic Moment Calculation**:
- The magnetic moment is calculated using the formula:
\[ \mu = \sqrt{n(n + 2)} \]
where \( n \) is the number of unpaired electrons.
- For the given transition metals:
- **Mn²⁺**: Configuration is \( 3d^5 \) → 5 unpaired electrons.
- **Fe²⁺**: Configuration is \( 3d^6 \) → 4 unpaired electrons.
- **Co²⁺**: Configuration is \( 3d^7 \) → 3 unpaired electrons.
- **Ni²⁺**: Configuration is \( 3d^8 \) → 2 unpaired electrons.
- Thus, the order of magnetic moments based on unpaired electrons is:
\[ \text{Mn²⁺} > \text{Fe²⁺} > \text{Co²⁺} > \text{Ni²⁺} \]

2. **Basic Character of Oxides**:
- The basic character of oxides decreases from left to right across the periodic table due to decreasing electropositivity.
- The order of basic character for the oxides is:
\[ \text{FeO} > \text{CoO} > \text{NiO} \]

3. **Oxidation States**:
- The oxidation states of the 3d series elements increase up to manganese and then start to decrease.
- The order of maximum oxidation states is:
\[ \text{Mn} > \text{Cr} > \text{Ti} > \text{Sc} \]
- This means manganese has the highest oxidation state, followed by chromium, titanium, and scandium.

4. **Magnetic Moment for 1 Unpaired Electron**:
- If there is 1 unpaired electron, the magnetic moment can be calculated as:
\[ \mu = \sqrt{1(1 + 2)} = \sqrt{3} \approx 1.732 \]

### Conclusion:
Based on the analysis:
- The order for magnetic moments is Mn²⁺ > Fe²⁺ > Co²⁺ > Ni²⁺.
- The order for basic character of oxides is FeO > CoO > NiO.
- The order for oxidation states is Mn > Cr > Ti > Sc.
- The magnetic moment for 1 unpaired electron is approximately 1.732.

Thus, the correct sequence of the indicated properties is:
1. Magnetic Moment: Mn²⁺ > Fe²⁺ > Co²⁺ > Ni²⁺
2. Basic Character: FeO > CoO > NiO
3. Oxidation States: Mn > Cr > Ti > Sc
4. Magnetic Moment for 1 unpaired electron: 1.732