Answer:
Option (a).
Step-by-step explanation:
The expansion of any population depends on the physical environment and the availability of food. The population that has large tolerance range can spread and expand its population.
Lionfish lives natively in the tropical pacific. The natural range of lionfish is narrow. In the pacific, no natural routes of warm water are available between the Atlantic and pacific ocean. Due to this reason, the new population expansion is not the expansion of lionfish natural range.
Thus, the correct answer is option (a).