If L₁ and L₂ Are Actual and Theoretical Lengths of a Tongue

Multiple Choice

If L₁ and L₂ are actual and theoretical lengths of a tongue rail, d is heel divergence and t is thickness

A) sin ^-1 (d - t/L₁)
B) tan ^-1 (d - t/L₁)
C) sin ^-1 (d - t/L₂)
D) tan ^-1 (d - t/L₂)