问一道阅读题，来自magoosh premium

mailliw1UID: 3206693

Recently, however, researchers chose to experiment with a type of conditioning that involves exposing subjects to a tone followed by an odor, so that they soon exhibit a similar response to the tone as they would to the odor. The pairing of tones and odors presented several advantages. Neither wakes the sleeper (in fact, certain odors can promote sound sleep), yet the brain processes them and even reacts during slumber. Moreover, the sense of smell holds a unique non-verbal measure that can be observed -- namely sniffing. The researchers found that, in the case of smelling, the sleeping brain acts much as it does when awake: We inhale deeply when we smell a pleasant aroma but stop our inhalation short when assaulted by a bad smell. This variation in sniffing could be recorded whether the subjects were asleep or awake. Finally, this type of conditioning, while it may appear to be quite simple, is associated with some higher brain areas -- including the hippocampus, which is involved in memory formation.

According to the passage, sniffing, as it relates to the experiment described in the passage, primarily

A. poses both advantages and disadvantages to researchers
B. offers researchers a quantifiable physiological response that exhibits little variation between    sleeping and waking states
C. provides researchers with a means of observing certain behaviors
D. enables scientists to study the effect of sleep on memory consolidation
E.functions as a non-verbal measure of changes that occur in lower areas of the brain
这里楼主只复制了一段，主要是讨论B选项。答案是B，但是文中说的variation并不是sleeping和waking states的variation啊，这不是偷换概念了？而且下面的答案解析也是这么写的，但不知道为什么就是B了。
这是答案解析：Answer: (B)

Sniffing is a physiological response to an odor (“The sleeping volunteers reacted…associated odor…by sniffing). It differs little between sleep and waking (“…could be recorded…asleep or awake”). Therefore (B). Remember, the variation in sniffing refers to the differing intensity of the sniff, not to the variation of sniffing between sleeping and waking states.
求助高手

sharony115UID: 3414657

从原文中看出variation in sniffing是在sleeping和waking states都能检测到，睡着还是醒着variation都没有差别。B. offers researchers a quantifiable physiological response that exhibits little variation between    sleeping and waking states ，表达“睡眠和清醒状态之间的差异不大”，不知道解释清楚了吗

mailliw1UID: 3206693

sharony115 发表于 2013-8-21 11:03
从原文中看出variation in sniffing是在sleeping和waking states都能检测到，睡着还是醒着variation都没有差 ...

little没看清。。谢谢！

SSLLTY11UID: 3538412

sharony115 发表于 2013-8-21 11:03
从原文中看出variation in sniffing是在sleeping和waking states都能检测到，睡着还是醒着variation都没有差 ...

我想问下原文中的这句话“This variation in sniffing could be recorded whether the subjects were asleep or awake”和上面的那句话是矛盾的吗？既然睡着和醒着反应都一样，那如何区分是睡着的还是醒着的呢？

StudentTedUID: 3516169

谢谢分享