The acceleration of a flat-faced follower when it has contact with the flank of a circular arc cam, is given by

A. $${\omega ^2}{\text{R}}\cos \theta $$

B. $${\omega ^2}\left( {{\text{R}} - {{\text{r}}_1}} \right)\cos \theta $$

C. $${\omega ^2}\left( {{\text{R}} - {{\text{r}}_1}} \right)\sin \theta $$

D. $${\omega ^2}{{\text{r}}_1}\sin \theta $$

Answer: Option B