Analyze the following code:

class Circle

$\{$

public:

Circle$($double radius$)$

$\{$

radius $=$ radius;

$\}$

private:

double radius;

$\}$;

The program has a compilation error because it does not have a main function.

The program does not compile because Circle does not have a default constructor.

The program will compile, but you cannot create an object of Circle with a specified radius. The object will have an unpredictable value for radius.

The program has a compilation error because you cannot assign radius to radius.