(char* str) is not callable using argument types (string)

[Zaheer Ahmed via Digitalmars-d-learn]

I am Developing an Operating System in D Language and when want 
to Develop my writeln("Zaheer"); function, I pass String "Zaheer" 
and when receive, it says Error
Error: function kernel.dwriteln (char* str) is not callable using 
argument types (string)
I Tried to cast but still stuck. In C and C++ I built this 2 
times but D is giving this.