Ciritcal path (do I include an inverter)

Hey, in question 2b , why the inverter gate take in the count? After all, it’s not part of the critical path (because it runs parallel to the first gate).
Attaching the question as a picture.

The fact that in the lower bound we do not count inverters does not mean that in reality they do not have a delay. You must count all the gates along the paths to obtain a critical path.