The figure shows the intensity-wavelength relations of X-rays coming from two different Coolidge tubes. The solid curve represents the relation for the tube A in which the potential difference between the target and the filament is V
A and the atomic number of the target material is Z
A. These quantities are V
B and Z
B for the other tube. Then,
(a) V
A > V
B, Z
A > Z
B
(b) V
A > V
B, Z
A < Z
B
(c) V
A < V
B, Z
A > Z
B
(d) V
A > V
B, Z
A < Z
B