# In the following match each item given under the column $C_1$ to its correct answer given under the column $C_2$

$\begin{array}{1 1}(A)\;(a)-(iv),(b)-(i),(c)-(ii),(d)-(iii)\\(B)\;(a)-(i),(b)-(ii),(c)-(iv),(d)-(iii)\\(C)\;(a)-(i),(b)-(iv),(c)-(iii),(d)-(ii)\\(D)\;\text{None of these}\end{array}$

$\sin (x+y)\sin (x-y)=\sin ^2x-\sin ^2y$
$\cos (x+y)\cos(x-y)=\cos^2x-\sin ^2y$
$\cot (\large\frac{\pi}{4}$$+\theta)=\large\frac{1-\tan \theta}{1+\tan \theta} \tan (\large\frac{\pi}{4}$$+\theta)=\large\frac{1+\tan \theta}{1-\tan \theta}$
Hence (A) is the correct answer.