Q: How does the heart transport blood?


Read this paragraph and choose the correct option from the provided answers:

A screw is an inclined plane wrapped around a cylinder. When on a screw, inclined planes are called threads, which can be seen in the image above. The mechanical advantage of a screw increases with the density of the threads. The calculations to determine the IMA for a screw involve the circumference of the head of the screw and the thread width. When the screw is turned completely around one time, the screw penetrates by one thread width. So, if the circumference of the head of a screw is 3.0 cm and the thread width is 0.60 cm, then the IMA would be calculated by.

 Choices:

- blood pellets

- nerves

- muscles

- blood vessels


A:
blood vessels