A Block of Mass M Is Held Motionless on a Frictionless

Multiple Choice

A block of mass M is held motionless on a frictionless inclined plane by means of a string attached to a vertical wall as shown in the drawing.
-What is the magnitude of the tension in the string?

A) zero newtons
B) Mg
C) Mg cos $\theta$
D) Mg sin $\theta$
E) Mg tan $\theta$