The logic circuit shown in the diagram directly implements which of the Boolean expressions given below?

$((x+y)y^{\text{'}}{)}^{\text{'}}$

$x^{\text{'}}((xy{)}^{\text{'}}{x}^{\text{'}}{)}^{\text{'}}$

$y^{\text{'}}(x+y)$

$y^{\text{'}}+(x{y}^{\text{'}})$