Hi there,
as XXX in if( XXX ) must evaluate to boolean,
int a=5;
int b=5;
if(a=b){}
this won't work. this works in C++ though. that's probably where you got confused.
and as for the Question itself.. I think that is wrongly written and what it is trying to
test is whether you know the difference between | and | | .. assuming I am right, the answer should be all of them. what do you think?