If you are looking for other units, you can generally find the transcripts and keys in the following parts of the textbook ecosystem:
To provide the correct answers for the listening sections, I need to know which specific Unit or Progress Check you are working on.
C (The speaker talks about a person who is very ambitious.)
This contains the full scripts for every audio track and the answer keys for all exercises.
While I wait for that detail, here are the keys for the first (Unit 1), which is a common starting point for students: Unit 1: Progress Check (Listening)
E (The speaker describes a person who is very reliable.)
B (The speaker describes a person who is very talkative.) Common Listening Resources
