What symbolic symbol is used in the design of notre dame's west facade?

1. four
2. three
3. two
4. one

The imposing western façade of Notre-Dame is a harmonious ensemble based on an play between vertical and horizontal lines: four powerful buttresses rise to the towers as an attempt to reach towards heaven whilst two wide horizontal strips seem to bring the sanctuary made by men down to earth.
https://frenchmoments.eu/west-facade-of-notre-dame-cathedral-paris/
hope this helps