Inheritance is used toa.Reduce code duplicationb.all of the abovec.Improve code reusabilityd.add relations with existing classes

The correct answer is b. All of the above. Inheritance in programming is used to reduce code duplication, improve code reusability, and add relations with existing classes.

Here's a step-by-step explanation:

1. Reduce code duplication: Inheritance allows a class to inherit properties and methods from another class. This means that you don't have to write the same code again and again; once a method or property is defined in a parent class, it can be reused in all child classes.

2. Improve code reusability: As mentioned above, inheritance allows properties and methods to be defined once and reused multiple times. This makes the code more modular and easier to maintain and update.

3. Add relations with existing classes: Inheritance establishes a type of relationship between classes known as an "is-a" relationship. For example, if you have a class "Animal" and a class "Dog", the Dog class can inherit from the Animal class. This establishes that a Dog "is-a" type of Animal. This relationship makes the code more intuitive and easier to understand.