This answer is not about your textbook answer key, but cadences generally.
The names of cadences can vary, but the concepts don't.
First, identify a structural ending. For example, V to I is not a cadence... unless it actually ends some phrase or section. Look for phrase/section endings, then categorize their cadences.
Next, identify the two final chords. ...
I'm surprised ^2-^1 hasn't occurred to you yet. It's pretty satisfying, IMO, as it resolves by step.
A voicing of V7-I resolved with ^2-^1 in the soprano will often have no ^5 in the I chord, but that could very well be fine.