What add function would return $\text{'}4\text{'}?$

defadd$(x)$:return$(x+x)add(2)$

def add$(x)$:return$(x+x+x)add{(}^{\text{'}}{1}^{\text{'}})$

def add$(x)$ : return $(x+x)add{(}^{\text{'}}{4}^{\text{'}})$