GMAT Critical Reasoning (CR) | A new medical procedure replaces all three of the tiny

Here is my explanation.

A new medical procedure replaces all three of the tiny bones in the inner ear with a single piece of ultra-thin fiberglass. The procedure has been found to greatlyimprove hearing in people who have experienced damage to these bones, though it is useless to people whose hearing loss stems from a neurological malfunction. This procedure will benefit a relatively small percentage of the hearing-impaired population.

Which of the following can be concluded from the argument
...

---