Detect an error from the program below:

class no$123\{$

public:

int $a,b$;

no$123($int $a,$ int b$)\{$

$a=a$;

$b=b$;$,$

$\}$ ;

a$.$ no$123$ should be $123$ no

b$.$ there should not be ; after the $\}$

c$.$ no errors

d$.$ duplicated variable names a and $b$