Read the following statements regarding birds. Select the one which is incorrect.

Options

A. Feathers help birds to fly
B. Birds have heavy bony skeletons
C. Birds have a boat-shaped body that enables them to fly
D. Tail feathers are used for steering to maintain both balance and braking speed

Answer

To determine which statement regarding birds is incorrect, we can analyze each statement one by one:

1. **Feathers help birds to fly**: This statement is correct. Feathers are lightweight and provide the necessary lift for birds to fly.

2. **Birds have heavy bony skeletons**: This statement is incorrect. In fact, birds have lightweight bones that are often hollow, which helps reduce their overall body weight and enables them to fly more easily.

3. **Birds have a boat-shaped body that enables them to fly**: This statement is correct. The aerodynamic shape of a bird's body reduces air resistance and allows for efficient flight.

4. **Tail feathers are used for steering, maintaining balance, and braking speed**: This statement is also correct. The tail feathers play a crucial role in controlling the bird's direction and speed during flight.

After analyzing all the statements, we find that the second statement, "Birds have heavy bony skeletons," is the incorrect one.

### Step-by-Step Solution:
1. **Read the statements carefully**: Understand what each statement is saying about birds.
2. **Evaluate the first statement**: Confirm that feathers do help birds to fly.
3. **Evaluate the second statement**: Recognize that birds actually have lightweight, hollow bones, making this statement incorrect.
4. **Evaluate the third statement**: Acknowledge that the boat-shaped body of birds is indeed beneficial for flight.
5. **Evaluate the fourth statement**: Understand that tail feathers are essential for steering and balance in flight.
6. **Identify the incorrect statement**: Conclude that the statement about birds having heavy bony skeletons is incorrect.

### Final Answer:
The incorrect statement is: "Birds have heavy bony skeletons."