Question: What is a problem with this code?

1. String should be compared using == method instead of equals.
2. Modifying a collection while iterating through it can throw a ConcurrentModificationException.
3. The List interface does not allow an argument of type String to be passed to the remove method.
4. ArrayList does not implement the List interface.

Answer: The correct answer of the above question is Option B:Modifying a collection while iterating through it can throw a ConcurrentModificationException.