nullptr is a keyword introduced in C++11 and is meant to replace the use of both and C standard library macro NULL. Although integer literal  is a valid value to assign to pointers, it is hard for human readers and automated debuggers to detect uses of  in the context of initialization or assignment to pointers. The use of macro NULL is not type safe because the macro typecasts integer literal  to either void* or int depending on the particular compiler.

In contrast to macro NULL or integer literal , keyword nullptr provides a type safe value representing an empty pointer.

Given the following definition

int *pi {nullptr};

choose the best possible answer from the listed choices.