To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) Compilation fails - This option is incorrect. The code will compile successfully as there are no syntax errors.
Option B) Pi is approximately 3 - This option is incorrect. The code uses the format specifier %d, which is used for integer values. Since Math.PI is a double value, using %d will result in incorrect output.
Option C) Pi is approximately 3.141593 - This option is incorrect. Although the output format is correct for a double value, the precision is not specified. The default precision for double is usually 6, so the output will be rounded to 3.141593.
Option D) An exception is thrown at runtime - This option is correct. The code uses the format specifier %d for an integer value, but Math.PI returns a double value. When trying to format the double value with %d, an exception will be thrown at runtime.
The correct answer is D. An exception is thrown at runtime because the format specifier %d is not compatible with the double value Math.PI.