Ace Your C++ Skills 2025 – Rock the ‘Thinking in C++’ Challenge!

Explanation A singly-rooted hierarchy, like the one in Smalltalk, only allows for single inheritance, meaning that a class can only inherit from one parent class. This limitation forces every class to be part of a single inheritance tree as opposed to allowing for multiple inheritance. This can restrict the flexibility and modularity of a program, as different classes cannot be inherited from multiple sources to add specific functionalities. Therefore, the use of a singly-rooted hierarchy in C++ may not be the best design choice for more complex and diverse programs. Option A is incorrect as virtual functions are not a requirement for a singly-rooted hierarchy. Option B is also incorrect as the limitation does not necessarily increase memory usage, but rather restricts inheritance options. Option D is also incorrect as dynamic memory allocation can still be used in a singly-rooted hierarchy, just with the limitation of only having one parent class.