Which of the following are benefits of using classes in C++ programming?Data Abstraction and EncapsulationReduced complexityIncreased execution speedCode maintenance and reusability

The benefits of using classes in C++ programming include:

1. Data Abstraction and Encapsulation: Classes in C++ help in bundling the data and the functions that operate on them as a single unit. This is known as encapsulation. The data is not accessible to the outside world, and only those functions which are wrapped in the class can access it. This abstraction of data is a very important feature of classes in C++.

2. Reduced Complexity: By using classes, we can divide a complex problem into smaller sets by creating objects. This makes the program easier to understand, manage and also reduces the complexity.

3. Code Maintenance and Reusability: Classes in C++ support the properties of procedural and object-oriented programming languages. The code written in C++ is reusable, which helps in saving time and effort. The code written in classes can be reused in many applications. The maintenance of the code becomes easier.

However, it's important to note that using classes does not necessarily increase execution speed. The execution speed of a program depends on various factors like the efficiency of the algorithm used, the capability of the processor, etc. Using classes can make the program more organized and manageable, but it doesn't directly contribute to the speed of execution.