Depth or height of the arch is the________________?

(A) perpendicular distance between intra-dos and extrados ()
(B) vertical distance between springing line and intrados (X)
(C) perpendicular distance between springing line and extrados (X)
(D) none of the above (X)

Answers: Depth or height of the arch is the perpendicular distance between intra-dos and extrados.