Reflection across the x axis involve negating the value of the y axis but the value of the x axis remain the same. Reflection across the y axis negate the x coordinates but the y values remains the same. When you reflect across the line y=x the coordinate and the y coordinates change places. Whe it rotate 180 degree around the origin the x and y values are negated. The transformation is interpreted as follows.
The answer is C which is reflection across the y axis followed by a 180 degree rotation around the origin.
The logic here is that PQRS is first reflected across the x axis which makes the y values negative. Then it reflect across the y axis which makes the value of x negative. So both x and y values are negative at this point. The rotation of 180 degree around the origin negates both the x and y values to make it all positive like the initial values of PQRS.