Advertisers who check web server logs may find their ads received multiple clicks from a single Internet Protocol (IP) address. This could be a result of:

• Query parsing being used to show geo-targeted ads to users in a different city.
• Incorrect IP address information filtered from Google Analytics.
• Internet Service Providers (ISPs) who assign the same IP address to multiple users.
• Duplicate keywords added to multiple ad groups in one campaign.

The correct answer is:

• Internet Service Providers (ISPs) who assign the same IP address to multiple users.