(B) magnanimous behavior can be regulated by the presence of absence of certain chemicals in the brain.
(C) magnanimous behavior can be regulated by the presence or absence of certain chemicals in the brain.
只有红色字体不同，是否按2楼的改正？
另外，Recent research as shown that they activity of these white blood cells is stimulated by beneficial chemicals produced by the brain as a result of magnanimous behavior.
they是否错，应为the？
Reference:
In my view, the reasoning in this argument is that:
magnanimous behavior＝》 beneficial chemicals produced by the brain＝》 they activity of these white blood cells＝》fight infection
So, the correct answer is D.
A is out of scope. Because unselfish motives is not mentioned in this argument.
B and C have the same mistake. From the above reasoning , it is clear that because of magnanimous behavior, some beneficial chemicals were produced by the brain. But the statement of B and C fail to convince us that magnanimous behavior can be regulated by the presence of absence of certain chemicals in the brain.
E is out of scope. The argument fails to establish the casual relationship between the number of white blood and the rate of magnanimous behavior.
对画线部分有另外的理解，原文应该存在下面推理：
1、magnanimous behavior＝》beneficial chemicals produced by the brain=》they activity of these white blood cells；
2、The bone marrow and spleen－》white blood cells－》fight infection
其中，原文一样没有提及they activity of these white blood cells与fight infection的关系，并不能证明stimulate activity导致更加fight infection，这里我们只能根据常识判断。当然，这里这个选项是best。
我认为应该这样解释：
1、doing good deeds＝》benefits one’s immune system
2、magnanimous behavior 《＝》good deeds（良好行为）
所以推出E。 | 
