Answer
C. When Fred came home from school, he was in a bad
mood.
<h3>
Answer: No, it is not a run-on sentence</h3>
This is one full thought that doesn't run on for too long. The "overcome with joy" portion is the dependent clause that needs the other part "Mrs. Monroe told her husband the exciting news about her promotion" which is the independent clause. The independent clause could be its own sentence without the dependent clause, but not the other way around.
