Given: 34. HashMap props = new HashMap(); 35. props.put("key45", "some value"); 36. props.put("key12", "some other value"); 37. props.put("key39", "yet another value"); 38. Set s = props.keySet(); 39. // insert code here What, inserted at line 39, will sort the keys in the props HashMap?
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Arrays.sort(s);
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s = new TreeSet(s);
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Collections.sort(s);
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s = new SortedSet(s);
B
Correct answer
Explanation
To sort the keys from a HashMap, you can create a TreeSet from the keySet() - TreeSet automatically sorts elements using their natural ordering (alphabetical for strings). Arrays.sort() doesn't work on Sets directly, Collections.sort() works on Lists, and SortedSet is an interface that cannot be instantiated directly. Option B correctly uses TreeSet to achieve sorting.