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 given code snippet does not contain any syntax errors, so it will compile successfully.
Option B) Pi is approximately 3 - This option is incorrect. The code snippet uses the format specifier "%d" in the format string, which is used for integers. Since Math.PI is a double value, using "%d" would result in incorrect output.
Option C) Pi is approximately 3.141593 - This option is incorrect. The code snippet does not specify the precision or decimal places to be displayed. By default, the decimal places are limited, so the output would not display the full value of Math.PI.
Option D) An exception is thrown at runtime - This option is correct. The code snippet tries to format a double value using the format specifier "%d" which is used for integers. This will result in a runtime exception, specifically a java.util.IllegalFormatConversionException.
The correct answer is D. An exception is thrown at runtime because the format specifier (%d) used is incompatible with the type of value (double) being passed.