Which of the following best describes the mode of action for benzimidazoles?

The correct answer is that benzimidazoles inhibit energy metabolism in helminths. This class of anthelmintic agents works primarily by binding to the β-tubulin of the parasites, disrupting the microtubule formation essential for cellular functions. By inhibiting the formation of microtubules, benzimidazoles effectively disrupt intracellular transport and cellular division, leading to impaired energy metabolism in the helminths. This ultimately results in the death of the parasites.

Other options present different mechanisms that do not accurately reflect how benzimidazoles operate. For instance, altering the host's immune response does not align with the direct action of benzimidazoles, nor do they act by paralyzing host tissue or promoting nutrient absorption in parasites. These mechanisms are characteristic of other types of anthelmintics or therapeutic approaches, highlighting the specific and well-defined action of benzimidazoles in inhibiting energy metabolism as the most accurate description of their mode of action.