Why does the Audi A1 use a four-link rear suspension?

I've noticed that the Audi A1 uses a four-link rear suspension instead of a multi-link or torsion beam setup. What are the benefits and drawbacks of this suspension design and how does it affect the car's handling and ride comfort?

The four-link rear suspension in the Audi A1 provides better handling and stability at high speeds compared to a torsion beam setup. However, it may affect the car's ride comfort on rough roads.

The four-link rear suspension allows for greater independent movement of the rear wheels, improving traction and cornering capability. However, it may also increase production costs and add weight to the car.