E. audience gave a well-deserved is the correct answer.
Explanation:
The complete sentence would look like this: "The circus audience gave a well-deserved round of applause for the perfectly timed acrobatic stunt." Since a round of applause is a way to show respect or to appreciate other people's work, it is logical to think that the audience was thankful for the dedication the acrobats put to execute in a perfect time their act. It is also necessary to include the hyphen since well-deserved is an adjective that modifies the noun "round of applause."
