Which of the following specification is most accurate ?

Options

A. `63.1xx10^(2)m`
B. `6.31xx10^(3)m`
C. 6310 m
D. `0.0631xx10^(5) m`

Answer

To determine which of the given specifications is the most accurate, we need to analyze each option based on how precisely they indicate the last significant digit.

### Step-by-Step Solution:

1. **Understanding Accuracy in Measurements**:
- Accuracy refers to how close a measurement is to the true value. In terms of significant figures, the more digits that are specified, the more accurate the measurement is considered to be.

2. **Analyzing Option 1: 63.1 × 10²**:
- This option is equivalent to 6310. However, the number 63.1 suggests that the last digit (1) is uncertain. Therefore, this option does not clearly specify the last digit, making it less accurate.

3. **Analyzing Option 2: 63.1**:
- Similar to option 1, this number does not indicate the precision of the last digit. It only specifies three significant figures, which does not provide a clear ending point. Thus, this option is also not the most accurate.

4. **Analyzing Option 3: 6310**:
- This option clearly indicates that the last digit is 0, and there is no ambiguity about the measurement. It specifies four significant figures, making it the most precise and accurate option among the four.

5. **Analyzing Option 4**:
- This option is not provided in the question, but if it were similar to the previous options (like 63.10 or any other variation), it would likely also lack clarity about the last significant digit, thus making it less accurate than option 3.

6. **Conclusion**:
- After analyzing all options, it is clear that option 3 (6310) is the most accurate specification as it clearly indicates the last significant digit without ambiguity.

### Final Answer:
- The most accurate specification is **Option 3: 6310**.