An advertiser notices that the click through rate (CTR) in one ad group has significantly decreased throughout the past few weeks. What could this advertiser do in an attempt to increase CTR and maintain relevant website traffic?

An advertiser notices that the click through rate (CTR) in one ad group has significantly decreased throughout the past few weeks. What could this advertiser do in an attempt to increase CTR and maintain relevant website traffic?
Ans: Use keyword matching options to help remove irrelevant searches.