The correct answer is: C. Java
Google added Java as the second programming language for App Engine development in 2008. This was done in order to make App Engine more accessible to a wider range of developers. Java is a popular and well-known programming language, and it is used by many developers around the world. Adding Java support to App Engine made it easier for these developers to use the platform.
C++ is a powerful programming language that is used for a variety of applications, including game development and system programming. However, it is not as widely used as Java, and it can be more difficult to learn. Flash is a multimedia platform that is used to create interactive content, such as games and animations. It is not a programming language, and it is not suitable for developing web applications. Visual Basic is a programming language that is used to create Windows applications. It is not as popular as Java or C++, and it is not suitable for developing web applications.
In conclusion, Google added Java as the second programming language for App Engine development in 2008. This was done in order to make App Engine more accessible to a wider range of developers. Java is a popular and well-known programming language, and it is used by many developers around the world. Adding Java support to App Engine made it easier for these developers to use the platform.