In the production of X-rays by a Coolidge tube, the changes which can be made in its operation are listed in column I. The possible effects of such changes are listed in column-II

COLUMN-I                                                                          COLUMN-II

A) Change in the current flowing through           P) Harder or softer X-rays are

The filament (emitter of cathode)                             produced

B) Change in the potential difference applied    Q) wavelengths of the

      Across the tube                                                          characteristic X-rays change 

C) Change in the metal used as the target           R) Intensity of the X-rays

                                                                                         change

D) Rotating the tube from a horizontal                  S) cut of wavelengths

         position to a vertical position                               changes