Match List - I with List - II and choose the correct answer.

List - I	List - II
(a) Cristae	(i) Primary constriction in chromosome
(b) Thylakoids	(ii) Disc-shaped sacs in Glogi apparatus
(c) Centromere	(iii) Infoldings in mitochondria
(d) Cisternae	(iv) Flattened membranous sacs in stroma of plastids

The correct option is a - (iii) b - (iv) c - (i) d - (ii).

Let us analyze and match the items in List - I with their correct descriptions in List - II step-by-step:

(a) Cristae:
Cristae are the numerous infoldings of the inner membrane of mitochondria. They increase the surface area available for chemical reactions, such as cellular respiration. Therefore, (a) matches with (iii).

(b) Thylakoids:
Thylakoids are flattened, membranous sacs found within the stroma of chloroplasts (plastids) where the light-dependent reactions of photosynthesis take place. Therefore, (b) matches with (iv).

(c) Centromere:
The centromere is the primary constriction region in a chromosome where the sister chromatids are joined and to which spindle fibers attach during cell division. Therefore, (c) matches with (i).

(d) Cisternae:
Cisternae are the flattened, disc-shaped sacs that make up the Golgi apparatus. They are stacked parallel to each other and are involved in the packaging and modification of proteins and lipids. Therefore, (d) matches with (ii).

Combining all the correct matches:
(a) → (iii)
(b) → (iv)
(c) → (i)
(d) → (ii)