If a resistor Rx is connected between nodes X and Y, Ry between X and Y, Rz between Y and Z to form a delta connection, then after transformation to star, the resistance at node Z is?

If a resistor Rx is connected between nodes X and Y, Ry between X and

1.	If a resistor R_x is connected between nodes X and Y, R_y between X and Y, R_z between Y and Z to form a delta connection, then after transformation to star, the resistance at node Z is?
A.	R<sub>y</sub>R<sub>x</sub>/(R<sub>x</sub>+R<sub>y</sub>+R<sub>z</sub>)
B.	R<sub>y</sub>R<sub>x</sub>/(R<sub>x</sub>+R<sub>y</sub>+R<sub>z</sub>)
C.	R<sub>z</sub>R<sub>y</sub>/(R<sub>x</sub>+R<sub>y</sub>+R<sub>z</sub>)
D.	(R<sub>z</sub>+R<sub>x</sub>)/(R<sub>x</sub>+R<sub>y</sub>+R<sub>z</sub>)
Answer» D. (R<sub>z</sub>+R<sub>x</sub>)/(R<sub>x</sub>+R<sub>y</sub>+R<sub>z</sub>)