Step 1: We need to identify the word pair where the relationship is different from the others.
- ``Error" and ``Accurate" are antonyms, as ``Error" means something incorrect and ``Accurate" means correct.
- ``Careless" and ``Casual" are related words but they do not form an antonymic relationship. ``Careless" refers to lack of attention, while ``Casual" refers to something relaxed or informal, not necessarily opposite.
- ``Strength" and ``Lethargy" are antonyms, as ``Strength" refers to power and ``Lethargy" refers to weakness or lack of energy.
- ``Gloomy" and ``Cheerful" are antonyms, as ``Gloomy" refers to being sad and ``Cheerful" refers to being happy.
Step 2: The odd pair is (B) ``Careless : Casual" because it does not represent an antonymic relationship like the others.
Thus, the correct answer is option (B) Careless : Casual.
Statement: All flowers are beautiful. Some beautiful things are fragile.
Conclusion I: Some flowers are fragile.
Conclusion II: All beautiful things are flowers.