This code returns a reference to an object. It should compile, but something is wrong. What is wrong?

Foo& someFunction$($int i$)$

$\{$

$$ Foo f;

$$ f$.$doSomethingIncredible$($i$)$;

$$ return f;

$\}$

a$.$ It returns a reference to a local variable that is destroyed $($goes out of scope$)$ when the function exits

b$.$ Variable i should be passed by pointer

c$.$ You cannot return a variable by reference