The tapeworm grows and reproduces in the digestive tract.
The option which would most likely result in the greatest decrease in the rate of a chemical reaction is adding an enzyme inhibitor to a reaction catalyzed by an enzyme.
Enzyme inhibitor is known for slowing down any processes, especially when it comes to chemical reactions, so I'd say A is the correct answer.
If the chemical touches another chemical, then there is a higher probability that it's going to react.
He should raise his hand and wait for a teacher