Which sentence contains an inappropriate shift in tense?
a. Sometimes the dog runs around and chases its own tail.
b. As the children play, Jonah is happy to relax with a book.
c. Lauren laughed out loud after she listens to joke.
Your answer is C. The reason is because Lauren laughed (past tense laugh) out loud after she listens (present tense listen) to a joke.
That is an improper shift in tense.
