HELP PLEASE A preservation biologist conducted an experiment on two islands (A and B) of similar size, climate, species composition, and richness. Originally, a large population of the same invasive species, a brown tree snake, was present on both islands. It had led to the extinction of some native lizards and forest birds. In her experiment, the biologist removed the brown tree snake from island B but not from island A. She then recorded the number of animal species on each island over a period of 24 months. The data collected is shown in the graph below:

Analyze the data above in terms of interspecific relationships and communities. Which statement best explains the difference in species present on each island over the course of the experiment?

The scientist is the ecosystem engineer of island B.
The brown tree snake was a keystone species on island B.
The brown tree snake is a foundation species on island A.
The brown tree snake is the ecosystem engineer on island A.