In the given question, a sentence is given with a part of it missing and represented by a blank. Choose the phrase that can be placed in the given blank to make a meaningful and grammatically correct sentence.
To reach the conclusion, the researchers examined the link between long-term exposure to air pollution and dementia and what role cardiovascular diseases _______.
1
play in that association
2
descend in that association
3
control in that association
4
assembling association
5
None of these