Which of the following is a possible Roman number?

Options

A. MCDVVXII
B. MCDXIV
C. MMMXVIX
D. MMDMXXII

Answer

To determine which of the given options is a possible Roman numeral, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding Roman Numerals**:
Roman numerals are represented by combinations of letters from the Latin alphabet: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). Certain rules govern how these letters can be combined.

2. **Analyzing the First Option: MCDVVX11**:
- Breakdown the letters:
- M = 1000
- C = 100
- D = 500
- V = 5 (but V cannot appear more than once in succession)
- X = 10
- The digits "11" are not valid in Roman numerals.
- Conclusion: This combination is invalid due to the presence of repeated V's and the digits "11".

3. **Analyzing the Second Option: MCDXVI**:
- Breakdown the letters:
- M = 1000
- C = 100
- D = 500
- X = 10
- V = 5
- I = 1
- Calculation:
- M + (D - C) + X + V + I = 1000 + (500 - 100) + 10 + 5 + 1
- = 1000 + 400 + 10 + 5 + 1 = 1416
- Conclusion: This combination is valid as it follows the rules of Roman numerals.

4. **Analyzing the Third Option: MMMXIX**:
- Breakdown the letters:
- M = 1000 (three times = 3000)
- X = 10
- I = 1
- IX = 9
- Calculation:
- MMM + X + IX = 3000 + 10 + 9 = 3019
- Conclusion: This combination is valid.

5. **Analyzing the Fourth Option: MMDXXI**:
- Breakdown the letters:
- M = 1000 (twice = 2000)
- D = 500
- X = 10 (twice = 20)
- I = 1
- Calculation:
- MM + D + XX + I = 2000 + 500 + 20 + 1 = 2521
- Conclusion: This combination is valid.

### Final Conclusion:
Among the options analyzed, the second option (MCDXVI) is a valid Roman numeral.