(i)-c , (ii)-a , (iii)-d , (iv)-b

(i) In square close packing each sphere is in contact which nearby 4 spheres. Thus it has a coordination number 4.

(ii) In hexagonal close packing in 2 dimension each sphere is in contact which nearby 6 spheres. Thus it has a coordination number 6. This arrangement creates triangular voids.

(iii) In hexagonal close packing in 3 dimension, there is repetition of pattern of sphere in alternate layers to form ABAB kind of pattern.

(iv) Cubic close packing in 3 dimensions has repetition pattern of spheres in every fourth layer thus forming ABCABC kind of pattern.