You need to write a console application that meets the following requirements:
* If the application is compiled in Debug mode, the console output must display Entering debug mode.
* If the application is compiled in Release mode, the console output must display Entering release mode.
Which code should you use?

Correct Answer: B
Explanation
When the C# compiler encounters an #if directive, followed eventually by an #endif directive, it will compile the code between the directives only if the specified symbol is defined. Unlike C and C++, you cannot assign a numeric value to a symbol; the #if statement in C# is Boolean and only tests whether the symbol has been defined or not. For example,
#define DEBUG
// ...
#if DEBUG
Console.WriteLine("Debug version");
#endif