Which keyword is used to define a derived class in C++?AsubclassBextendsC: publicDinherits

In C++, the keyword used to define a derived class is : public. This syntax is part of the class declaration and indicates that the new class (the derived class) inherits from an existing class (the base class).

Explanation:

1. Base Class and Derived Class: In C++, you can create a new class based on an existing class. The existing class is known as the base class, while the new class is referred to as the derived class. The derived class inherits properties and behaviors (methods) from the base class.

2. Access Specifiers: The public keyword in : public BaseClass specifies the inheritance mode. It indicates that members of the base class that are public will also be accessible in the derived class. There are other access specifiers like protected and private, which can change the accessibility of base class members in the derived class.

So, in this question, the correct choice from the given options is C: public. This syntax indicates that the derived class has a public inheritance relationship with the base class.