The play has been on for two hours so the audiences are very tired. {A; B; C} A. 这部剧已经演了两个小时了，所以演员们很

The play has been on for two hours so the audiences are very tired. {A; B; C} A. 这部剧已经演了两个小时了，所以演员们很累了。 B. 这部剧两个小时就演完了，所以观众们不是很累。> C. 这部剧已经演了两个小时了，所以观众们很累了。

The original sentence states that the play has been ongoing for two hours, resulting in tired audiences. Let's analyze the options:

Option A incorrectly mentions "actors" instead of "audiences."

Option B distorts the meaning by claiming the play "finished in two hours" and audiences "are not tired," contradicting the original statement.

Option C accurately translates both the duration ("has been on for two hours") and the consequence ("audiences are very tired").

Answer: C