**Explanation:**

The correct answer is option **D) Talons**.

**Birds have sharp claws called talons** that are used for various purposes such as catching prey, perching, climbing, and defending themselves. Talons are specialized adaptations of bird's feet that help them to grasp and hold onto objects.

**Here is a detailed explanation of the answer:**

1. **Birds have specialized feet**: Birds have specialized feet that are adapted for different functions depending on their lifestyle and habitat. These adaptations include webbed feet for swimming, strong legs for walking or running, and talons for capturing and holding prey.

2. **Talons are sharp claws**: Talons are sharp claws at the end of a bird's feet. They are curved and pointed, allowing the bird to grab onto objects with a strong grip. Talons are usually found on the toes of birds, with some birds having three toes pointing forward and one pointing backward (zygodactyl) and others having four toes pointing forward (anisodactyl).

3. **Used for catching prey**: Birds of prey, such as eagles, hawks, and owls, have powerful talons that are used for catching and holding onto their prey. They swoop down from the sky and use their sharp talons to grasp their prey tightly, preventing it from escaping.

4. **Used for perching**: Many birds use their talons for perching on branches, wires, or other surfaces. The sharp claws allow them to grip onto the surface securely, even when they are sleeping or resting.

5. **Used for climbing**: Some birds, such as woodpeckers and parrots, use their talons for climbing trees or other vertical surfaces. They can grip onto the bark or other rough surfaces with their sharp talons, allowing them to move up and down easily.

6. **Used for defense**: Birds may use their talons for defense when they feel threatened. They can use their sharp claws to strike or scratch potential predators, deterring them from attacking.

In conclusion, the sharp claws of birds are known as talons. These talons are specialized adaptations of bird's feet that enable them to catch prey, perch, climb, and defend themselves.

Legs is correct.