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.

[Q]: Some scientists predict that as greenhouse gases change the climate of Earth, the number and strength of hurricanes will increase. In order for this to occur, the climate change would have to affect Earth by changing the  
 (A) depths of the oceans. (B) speed of currents in the oceans. (C) chemical compositions of the oceans. (D) amount of dissolved oxygen in the oceans.
[A]: B


[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.
[A]: B


[Q]: Scientists are concerned about the presence of heavy metals like lead and mercury in the environment because  
 (A) heavy metals threaten some forms of life. (B) heavy metals will increase available resources. (C) exposure to heavy metals causes healthy mutations. (D) mining for heavy metals causes environmental stability.
[A]:
A