Which differential trace impedance should I choose, 85 ohm or 100 ohm?

On the P3737_A05_OrCAD_schematics(base_version).pdf file,the pcie clk differential trace impedance is both 85 ohm on the page of the M.2 Key M Connector and the M.2 Key E Connector. The pcie clk differential trace impedance of my pcie thernet PHY is 100 ohm. So, which differential trace impedance should I choose, 85 ohm or 100 ohm?

PCIe Gen 2 typically uses a 100-ohm differential impedance, while PCIe Gen 3, along with subsequent generations, generally utilizes a 85-ohm differential impedance. 85-ohm differential impedance is preferred, however, please check with your ethernet PHY vendor.

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