Answer:
Your answer would be sentence 4 (the swimmer, her shoulder injury finally healed...).
Step-by-step explanation:
An absolute phrase is a phrase that modifies a noun in a sentence, but it is not connected to the sentence by a conjunction. It is offset with commas and can be removed without altering the meaning of the sentence. In the sentence above, the absolute phrase is the NP her shoulder injury finally healed. This NP modifies the noun swimmer.
The absolute phrase can be removed without changing the meaning of the sentence (see II).
I) The swimmer, her shoulder injury finllay healed, dove into the pool
II) The swimmer dove into the pool