Concept:The task is to choose the word most nearly opposite in meaning to the underlined word “stellar”.
Explanation:The word “stellar” means outstanding, excellent, or exceptional.
The sentence contrasts the rockstar’s excellent performance with the amateur group’s showing.
Therefore, the missing word should have the opposite meaning, such as ordinary or unimpressive.
The word “mundane” means dull, ordinary, or commonplace.
So “mundane” is the most suitable opposite of “stellar” in this context.
Answer:C. mundane