Which one of the following is true for 0° < θ < 90° ?

Answer: Option C

$$\begin{array}{rl}& \text{Put, }\theta =60^{\circ }\\ & \Rightarrow \cos \theta >{\cos }^2\theta \\ & \Rightarrow \cos 60^{\circ }>{\cos }^{2}60^{\circ }\\ & \Rightarrow \frac{1}{2}>\frac{1}{4}\\ & \cos \theta >{\cos }^2\theta \end{array}$$