Question

read the passage.
saving sea turtles
small - scale fishing performed with nets is one of the most common fishing methods used around the world. one of the unfortunate side effects of this method is that sea turtles, which are considered threatened, get caught in the nets along with the fish. conservation biologists at the university of exeter in england recently devised a way to prevent these sea turtle deaths, which they tested at a fishery in northern peru. they found that attaching green led lights to the nets warned the turtles away, possibly because the lights made the nets more visible. the number of sea turtle deaths was reduced, but the number of fish caught seemed to remain the same.
what is the main, or central, idea of the passage?
conservation biologists are researching ways to save the threatened sea turtle population.
to prevent turtles from becoming caught in fishing nets, conservation biologists attached led lights to the nets.
one problem with small - catch fishing is that sea turtles get caught along with fish.

Explanation:

The passage starts by introducing the problem of sea turtles getting caught in small - scale fishing nets. Then it focuses on the solution that conservation biologists came up with: attaching green LED lights to the nets. The first option is too general as it just says they are researching ways, not specifying the method. The third option only states the problem, while the second option accurately describes the main action (attaching LED lights to nets) taken to solve the problem of turtles being caught.

Answer:

B. To prevent turtles from becoming caught in fishing nets, conservation biologists attached LED lights to the nets.