**Answer:**

The correct answer is option 'A', the Stork bird.

**Explanation:**

Stork birds have long legs and thin toes that prevent them from sinking in mud. Let's understand why this is the case:

1. **Physical Features of Stork Bird:**
- Stork birds are known for their long legs and long bills.
- They have strong and sturdy legs that allow them to wade through shallow water and marshy areas.
- Their legs are long enough to keep their bodies above the water surface.
- Stork birds also have long toes that are well adapted for walking on various surfaces, including mud.

2. **Adaptations for Walking on Mud:**
- The long legs of the Stork bird elevate its body above the mud, preventing it from sinking.
- The thin toes of the Stork bird distribute its weight over a larger surface area, reducing the pressure on the mud.
- This adaptation helps the Stork bird to walk on mud without sinking and allows it to move around easily in wetland habitats.

3. **Habitat and Feeding Behavior:**
- Stork birds are commonly found in wetland habitats, such as marshes, swamps, and shallow water bodies.
- They are excellent waders and use their long legs and thin toes to walk through muddy areas in search of food.
- Stork birds mainly feed on fish, frogs, small reptiles, and insects that inhabit these wetland areas.

4. **Other Birds:**
- Woodpecker birds have short legs and stout toes that are adapted for climbing tree trunks and pecking on wood, not for walking on mud.
- Tailor birds and Kite birds also do not have long legs and thin toes that prevent them from sinking in mud.

In conclusion, the Stork bird has long legs and thin toes that prevent it from sinking in mud, making it the correct answer to the given question.

A