Show how answer is B in simple and understable stepsThe rate of change of a given function $f(x,y)$ at the point $P_0=(1,2)$ in the direction

towards $P_1=(2,3)$ is $2\sqrt[\phantom{2}]{2}$ and in the direction towards $P_2=(1,0)$ is $-3.$ What is the rate of

change of $f$ at $P_0$ towards the origin $P_3=(0,0)?$

A$.-\frac{3}{2\sqrt[\phantom{2}]{2}}$

B$.-\frac{7}{\sqrt[\phantom{2}]{5}}$

C$.\frac{2}{\sqrt[\phantom{2}]{2}}$

D$.\frac{3}{\sqrt[\phantom{2}]{5}}$

E$.$ None In previous solution, How have you computed STEP$3?$ Show me how step $3$ is computed