Final answer:
The best option for addressing the environmental concern about transgenic Atlantic salmon escaping into the wild is by restricting salmon breeding.
Step-by-step explanation:
The best option for addressing the environmental concern about transgenic Atlantic salmon escaping into the wild is by restricting salmon breeding (option A)
This can be achieved by implementing measures such as better containment methods in aquaculture facilities and regulations that limit the production and release of transgenic salmon into the wild.