What is wrong with the following program?

#include

int what$\_$is$\_2$x$281()\{$

int x$,$ y $=281$;

return x $+=$ y;

$\}//$ what$\_$is$\_2$x$281()$

int main$()\{$

std::cout $<<$ "What is $2$ x $281?$

$"<<$ what$\_$is$\_2$x$281()$;

$\}//$ main$()$

Group of answer choices

the $+=$ operator cannot be used after a return statement, since x would be returned before being added to y

what$\_$is$\_2$x$281()$ returns an uninitialized value

the type of y is undefined

main$()$ must have a return statement

nothing is wrong with this program