Final answer:
Option (d), To control problem birds, exclusion, trapping, shooting, or avitrol are commonly used methods, but biological control is a more sustainable approach that utilizes natural organisms to manage pest populations, though it requires careful consideration of ecological impacts.
Step-by-step explanation:
The best way to control problem birds is by exclusion, trapping, shooting, or using avitrol. However, among the more environmentally sensitive and sustainable options, biological control, which is the use of organisms such as predators, parasitoids, and pathogens to control pest species, is another approach.
Biological control can be an effective strategy for dealing with invasive or problematic species, as it often results in long-term management without some of the negative impacts associated with chemical controls or mechanical removal methods.
Examples include the introduction of predatory insects to manage pest populations in agricultural settings, or the use of specific animal species to control rodent populations. Nevertheless, it's important to consider potential non-target effects and the ecological balance before implementing a biological control program.