Expression in Terms of Theta

*A crate weighing $\displaystyle w$ pounds sits on a ramp positioned at an angle of $\displaystyle \theta$ with the horizontal. The forces acting on this crate are modeled by the equation $\displaystyle Mw cos \theta = w sin \theta$ , where $\displaystyle M$ is the coefficient of friction. What is an expression for $\displaystyle M$ in terms of $\displaystyle \theta$ ?*

a) $\displaystyle M = tan \theta$

b) $\displaystyle M = sec \theta$

c) $\displaystyle M = cot \theta$

d) $\displaystyle M = csc \theta$