# MATLAB - Probability Default with CDS Bootstrapping

I have not understood which "zerorati" I must use for the bootstrap of the PD from the curve of the CDS spreads. Can you help me please? I consulted O'Kane (2008) and Brigo and Mercurio (2006), but I'm not sure of the choice.

https://it.mathworks.com/help/finance/bootstrapping-a-default-probability-curve.html