In computer programming, which of the following statements best describes the role of local variables?
A) Local variables are accessible from any function or block within a program.
B) Local variables are used to store values that are shared across all functions in a program.
C) Local variables exist only within the function or block where they are declared and are not accessible outside of it.
D) Local variables retain their values throughout the entire execution of a program, even after the function has finished executing.