Question: Four identical candles are set on a safe surface and lit. One is covered with a small-sized jar, one is covered with a large-sized jar, and one candle is left in the open. A fourth lit candle is placed in a vacuum. Which candle will most likely stay lit the longest?

  Options: 
 A. the candle placed in the vacuum
 B. the candle covered with the small-sized jar
 C. the candle covered with the large-sized jar
 D. the candle left out in the open 
Answer: D