11. Which features adapt polar bears to live in extremely cold climates?
(i) A white fur, fat below the skin, keen sense of smell.
(ii) Thin skin, large eyes, a white fur.
(iii) A long tail, strong claws, and white large paws.
(iv) White body, paws for swimming, gills for respiration.
The features that adapt polar bears to live in extremely cold climates are white fur, fat below the skin, and a keen sense of smell. Thus, option (i) is correct.