The correct answer is: A. assign

The assign function is used to assign a value to a string variable. It takes two arguments: the first is the string variable to be assigned, and the second is the string to be assigned to the variable.

The copy function is used to copy a string from one location to another. It takes two arguments: the first is the source string, and the second is the destination string.

The string function is used to create a new string object. It takes one argument: the string to be created.

The strcopy function is used to copy a string from one location to another. It takes two arguments: the first is the source string, and the second is the destination string. However, it does not check to see if the destination string is large enough to hold the source string. If it is not, the destination string will be truncated.

Here is an example of how to use the assign function:

“`c++

include

include

int main() {
std::string str1 = “Hello”;
std::string str2;

str2.assign(str1);

std::cout << str2 << std::endl;

return 0;
}
“`

This code will print the following to the console:

Hello