To determine the language that is not a true object-oriented programming language, we need to understand the concept of object-oriented programming and the characteristics that define it.

Object-oriented programming (OOP) is a programming paradigm that uses objects, which are instances of classes, to represent and manipulate data. Key features of OOP include encapsulation, inheritance, and polymorphism.

Now let's go through each option and determine if it is a true object-oriented programming language:

A. VB.NET: VB.NET is a true object-oriented programming language. It is an evolution of Visual Basic and fully supports OOP concepts.

B. VB 6: VB 6, also known as Visual Basic 6, is not a true object-oriented programming language. While it has some object-oriented features, such as support for classes and objects, it lacks full support for OOP concepts like inheritance and polymorphism.

C. C++: C++ is a true object-oriented programming language. It supports all the key features of OOP, including encapsulation, inheritance, and polymorphism.

D. C#: C# is a true object-oriented programming language. It was specifically designed for the Microsoft .NET framework and fully supports OOP concepts.

E. Java: Java is a true object-oriented programming language. It was designed to be purely object-oriented and supports all the key features of OOP.

Based on the explanations above, the language that is not a true object-oriented programming language is:

B. VB 6

The Answer is: B