求助gwd一道逻辑,E为什么排除了

smilegmat

Though sucking zinc lozenges has been promoted as a treatment for the common cold, research has revealed no consistent effect.  Recently, however, a zinc gel applied nasally has been shown to greatly reduce the duration of colds.  Since the gel contains zinc in the same form and concentration as the lozenges, the greater effectiveness of the gel must be due to the fact that cold viruses tend to concentrate in the nose, not the mouth.

In order to evaluate the argument, it would be most helpful to determine which of the following?

	Whether zinc is effective only against colds, or also has an effect on other virally caused diseases
	Whether there are remedies that do not contain zinc but that, when taken orally, can reduce the duration of colds
	Whether people who frequently catch colds have a zinc deficiency
	Whether either the zinc gel or the lozenges contain ingredients that have an impact on the activity of the zinc
	Whether the zinc gel has an effect on the severity of cold symptoms, as well as on their duration

正确答案是D
我选的是E,E说了z g这个东西对severity of cold symptoms（感冒的严重性，我觉得原文说zg可以治疗感冒，所以可以说zg对感冒严重性有影响） 和duration（这个原文直接说了）有作用，为什么E不是正确答案