What happens when this C# code runs: object o = 5; long n = (long)o;?
Correct answer A. An InvalidCastException is thrown
Explanation
The value 5 is boxed as an int. Unboxing must be to the exact type that was boxed (or its nullable form), so casting the boxed int directly to long throws InvalidCastException at run time, even though int converts to long normally. The correct form is long n = (int)o;, which first unboxes to int and then widens implicitly to long.
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