Which of the following acids has the lowest $pK_a$ value?

The ratio of anion radius to cation radius of a crystal is $10: 9.3$. Then,the coordination number of the cation in the crystal is

If the axes are rotated through an angle $45^{\circ}$ in the positive direction without changing the origin,then the coordinates of the point $(\sqrt{2}, 4)$ in the old system are

From a disc of mass $M$ and radius $R$,a circular hole of diameter $R$ is cut such that its rim passes through the center of the disc. The moment of inertia of the remaining part of the disc about a perpendicular axis passing through the center of the original disc is

The length of the latus rectum of the parabola $y^2+8x-2y+17=0$ is

Match the following columns:

Column-$I$	Column-$II$
$(a)$ $Oscillatoria$	$(p)$ $Prothallus$
$(b)$ $Cycas$	$(q)$ $Cell$ $wall$ $contains$ $chitin$ $mixed$ $with$ $cellulose$
$(c)$ $Dryopteris$	$(r)$ $Primitive$ $flowers$
$(d)$ $Yeast$	$(s)$ $Food$ $stored$ $as$ $starch$