Final answer:
In the provided text passages, 'egress' is used to describe the act of exiting, as the characters transition from a darker place to one less confined. Hence, the correct definition of 'egress' is c) 'exit'.
Step-by-step explanation:
The term egress in sentences 45 and 50 of the provided text references the act of leaving or going out, which is synonymous with c) exit.
This is understood from the context of the text, where in sentence 45, the setting changes from a dark, silent place to an area where the air hisses and tongues babble, hinting at a transition out of a silent or isolated area.
In sentence 50, 'egress' is defined through Bess and Venters preparing to leave the narrow gorge, hence engaging in the act of egress or exiting from a confined space into a more open area.