Which strategy should Giorgio use to increase the number of relevant clicks from his Search Network campaign?

Which strategy should Giorgio use to increase the number of relevant clicks from his Search Network campaign?

• Broaden his keyword list for ads with the lowest clickthrough rate (CTR)
• Increase bids for ads with the lowest average position and clickthrough rate (CTR)
• Add new relevant keywords and remove keywords with low clickthrough rate (CTR)
• Increase bids on relevant keywords with low clicks and clickthrough rate (CTR)