Which of the following belongs to d-block element?

Options

A. `[Rn] 6d^(10) 7s^(2)7p^(2)`
B. `[Xe] 4f^(1)5d^(1) 6s^(2)`
C. `[Xe] 4f^(14) 5d^(1)6s^(2)`
D. `[Xe]5d^(1)6s^(2)`

Answer

To determine which of the given options belongs to the d-block elements, we need to analyze the electron configurations provided in the options. The d-block elements are characterized by having their last electrons entering the d subshell, and their general electronic configuration can be represented as:

\[ n - 1 d^{1-10} n s^{0-2} \]

where \( n \) is the principal quantum number.

### Step-by-Step Solution:

1. **Identify the Options**:
Let's denote the options as follows:
- Option A: Rn 6d10 7h2 7p2
- Option B: Rn 5f14 6d10
- Option C: Rn 7s2 7p2
- Option D: Rn 6d5 7s2

2. **Analyze Each Option**:
- **Option A**: Rn 6d10 7h2 7p2
- The last electrons enter the 7p subshell, indicating this is a p-block element.
- **Option B**: Rn 5f14 6d10
- The last electrons enter the 6d subshell, indicating this is a d-block element.
- **Option C**: Rn 7s2 7p2
- The last electrons enter the 7p subshell, indicating this is a p-block element.
- **Option D**: Rn 6d5 7s2
- The last electrons enter the 6d subshell, indicating this is a d-block element.

3. **Conclusion**:
From the analysis, we see that both Option B and Option D have their last electrons entering the d subshell. However, since the question asks for which of the following belongs to the d-block element, we can conclude that:
- **Correct Answer**: Option D (Rn 6d5 7s2) is the most straightforward representation of a d-block element.

### Final Answer:
**Option D** belongs to the d-block elements.