If Sb is the average bond stress on a bar of diameter d subjected to maximum stress t, the length of the embedment l is given by

A

$$I=\frac{dt}{S_b}$$

B

$$I=\frac{dt}{2S_b}$$

C

$$I=\frac{dt}{3S_b}$$

D

$$I=\frac{dt}{4S_b}$$