An advertiser who decides to edit the location targeting of an ad can do this at the:

An advertiser who decides to edit the location targeting of an ad can do this at the:

A)  ad group level
B)  keyword level
C)  campaign level
D)  account level

Answer : campaign level

Reason :

Sign in to your AdWords account at https://adwords.google.com.

• Click the Campaigns tab.
• Click the name of the campaign that you'd like to edit.
• Click the Settings tab.
• Click Edit next to Locations.
• Enter the name of the country that you'd like to target.
• Click Add to add the location.
• Click Save to save your settings.

Read more at https://support.google.com/adwords/answer/1722043?hl=en