Correct Option (b)
Statement 3: The passage provides a direct example of the Alabama leaf-worm, a cotton pest, which has developed resistance to multiple pesticides including Aldrin, DDT, dieldrin, endrin, lindane, and toxaphene. This illustrates that a single pest species can evolve resistance to a range of chemical pesticides. Therefore, statement 3 is correct.
Incorrect Options:
Statement 1: The passage states that in many poorer countries, the prospect of mass starvation or epidemic disease often leads to the justification of pesticide use, even if social and health costs are overlooked. However, it does not assert that the use of chemical pesticides has become "imperative in all" poor countries. The context suggests a strong justification in specific circumstances rather than a universal imperative. Therefore, statement 1 is incorrect.
Statement 2: The passage argues against the notion that chemical pesticides have no role in sustainable agriculture. It highlights that their production has increased, and the cost-benefit ratio often favors their use for agricultural producers. Furthermore, it suggests that their use can be described as sustainable in fundamental senses (e.g., lives saved, economic efficiency). The passage concludes that sustainability depends on developing new pesticides that are "less persistent, biodegradable and more accurately targeted." This implies a continued, albeit evolving, role for pesticides in sustainable agriculture. Therefore, statement 2 is incorrect.