The correct option is D To run on flat ground- c, To walk on muddy ground- a, To grip prey- d, To scratch for worms- b
Feet 'a' is well adapted to walk on muddy ground. It has a webbed structure which, enables better grip on muddy ground. Feet 'b' is well adapted to scratch on the ground for preying on worms. It is commonly seen as an adaptation of hens. Feet 'c' is very well adapted to run fast on ground, with all fingers close to each other. Whereas, the feet given as the last option 'd' is seen in eagles, vultures, etc. These birds use this kind of feet to grip on preys, like chicks.