Correct Answer: $\operatorname{sin}^2 \phi\cot ^2 \phi$

Solution : We know, $\sec^2 \phi-\tan^2 \phi$ = 1 and $\frac{\cos^2 \phi}{\sin^2 \phi}$ = $\cot^2 \phi$
So, $1-\frac{\tan^2 \phi}{\sec^2 \phi} $
= $\frac{\sec^2 \phi-\tan^2 \phi}{\sec^2 \phi}$
= $\frac{1}{\sec^2 \emptyset}$
= $\cos^2 \phi$
= $\frac{\sin^2 \phi\times{\cos^2 \phi}}{\sin^2 \phi}$
= $\sin^2 \phi\cot^2 \phi$
Hence, the correct answer is $\sin^2 \phi\cot^2 \phi$.