Consider the code snippet below.

int ch $=100$;

Which of the following is a legally correct way of obtaining the memory location of ch and printing it $($the memory location$)$ to standard output, based on the given code snippet?

cout $<<$ ch $<<$ endl;

$2.$cout $<<*$ch $<<$ endl;

$3.$cout $<<$&ch $<<$ endl;

$4.$cout $<<*($&ch$)<<$ endl;