The Closer the Rotation Center Is to the Teeth,the Narrower

The closer the rotation center is to the teeth,the narrower the focal trough.In most panoramic machines,the focal trough is wide in the anterior region and narrow in the posterior region.

A) Both statements are true.
B) Both statements are false.
C) The first statement is true;the second statement is false.
D) The first statement is false;the second statement is true.