Understanding the Question
The question presents four options, all of which include the year 1945 and variations in punctuation. The goal is to determine which option is correct based on implicit criteria.

Analysis of Options
- Option a) 1945 ..
- The use of two dots is unconventional in standard date formatting, making this option less likely to be correct.
- Option b) 1945
- This option presents the year in a clean, standard format without any additional punctuation, which is generally accepted as correct.
- Option c) 1955
- This option introduces a different year altogether, which is irrelevant to the core focus on the year 1945.
- Option d) 1945 . .
- Similar to option a, the use of two dots is also unconventional and does not conform to standard formatting.

Conclusion
The correct answer is option 'B' because:
- Standard Format: It follows the conventional way of writing a year without any unnecessary punctuation.
- Relevance: It stays focused on the specific year in question, maintaining clarity and simplicity.
In summary, the clarity and adherence to standard formatting make option 'B' the most appropriate choice among the given options.