Take a look at the sentence again:
When Noodle the poodle realized that the leash meant a bath, not a walk
to the park, he growled, pulled, and __________.
The blank needs to begin with a simple past tense verb. You chose was leaping like a fish on a line, which uses the past progressive tense and thus causes a parallelism error. Before you continue, review the rules for parallel structure.
Go back to the sentence to try again.