You are given a science question (hard-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

[EX Q]: A flowing stream contains water at 18°C. Cans of soft drinks at 28°C are lowered into the stream. Which of the following will most likely occur?  
 (A) The soft drink cans will absorb cold energy from the stream's water. (B) The cans will cool until their temperature is the same as the stream's. (C) The temperature of the soft drinks will not change since the cans are sealed. (D) The temperature of the cans will decrease to freezing as long as the stream is flowing.
[EX A]: B

[EX Q]: Sodium, Na, is in the same group as  
 (A) Ne. (B) Mg. (C) Ca. (D) K.
[EX A]: D

[EX Q]: 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?  
 (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
[EX A]:
D