You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Canadian_football

Context:
The clock does not run during convert attempts in the last three minutes of a half. If the 15 minutes of a quarter expire while the ball is live, the quarter is extended until the ball becomes dead. If a quarter's time expires while the ball is dead, the quarter is extended for one more scrimmage. A quarter cannot end while a penalty is pending: after the penalty yardage is applied, the quarter is extended one scrimmage. Note that the non-penalized team has the option to decline any penalty it considers disadvantageous, so a losing team cannot indefinitely prolong a game by repeatedly committing infractions.

Question:
What causes a quarter to be extended one additional play even if time has run out?

penalty