Comprehension:

In the following passage some of the words have been deleted. Read the passage carefully and select the correct answer for the given blank out of the four alternatives.

The thought here is that because saliva is (1) ________ alkaline, stimulating it by chewing gum after eating (2)_____ help neutralize the acidity in your mouth and throat. (3)______ a very small study from 2005 did (4)_______ some merit to this approach, the size of the study makes it difficult to (5)_______ any real conclusions.

Select the most appropriate option to fill in blank number 3. 

While

- The word suitable for the blank is 'while'.

- The complete sentence is :  While a very small study from 2005 did _______ some merit to this approach.

- By using "While" in the first blank, it introduces a contrast or contradiction to the preceding information. It indicates that despite the following statement about the small study from 2005, there might be differing or opposing perspectives or evidence regarding the approach being discussed