The most likely drug to be effective in diseases caused by cestodes and trematodes is
High-Yield Explanation
Praziquantel is the drug of choice for treatment of all fluke (trematode) infections and most tapeworm (cestode) infections. Its antihelminthic action derives from an increase in membrane permeability to Ca, which results in contraction, followed by paralysis, of worm musculature. Mebendazole also has antihelminthic activity, but it is restricted to the nematodes. The other drugs listed are antiprotozoals.