Final answer:
The sentence 'Susan saw a man with binoculars' has structural ambiguities related to both Susan's vision and the man's possession of binoculars.
Step-by-step explanation:
The structural ambiguity in the sentence 'Susan saw a man with binoculars' is related to the interpretation of the phrase 'with binoculars.'
One possible interpretation is that Susan saw a man who was holding binoculars. This relates to option a) Susan's vision and the man's possession of binoculars.
Another interpretation is that Susan saw a man through binoculars. This relates to option b) The man's appearance and Susan's vision.
Therefore, the correct answer is c) Both a and b.