Here's a problem to solve: Tapeworms live in the intestines of dogs and absorb nutrients from food the dog eats. Which best describes the outcome of this relationship?

Among the 4 following options, which is the correct answer?

- A: The dog and tapeworm both become ill.
 
- B: The dog becomes ill, and the tapeworm benefits.
 
- C: The tapeworm and dog help each other survive.
 
- D: The tapeworm helps the dog survive.
 