Regression testing should be performed: (V) Every Week. (W) after the software has been changed. (X)as often as possible. (Y)When the environment has changed. (Z)When the project manager says.
v & w are true, x – z are false
w, x & y are true, v & z are false
w & y are true, v, x & z are false
w is true, v, x y and z are false