You have an online electronics business and you’ve set up an ad group for digital cameras. What keywords could make this ad group as effective as possible?

• Brand names of your top competitors’ cameras
• Words from headlines on your website, like “electronics” and “sale on cameras”
• General phrases related to photography, like “camera lens” and “camera base”
• Words in your ad text, like model names of digital cameras

The correct answer is: Words in your ad text, like model names of digital cameras

Explanation: You have an online electronics business and you’ve set up an ad group for digital cameras. Using words in your ad text, like model names of digital cameras,can make this ad group as effective as possible. Keywords in your ad text show your ad’s relevance to what people want. For example, if you’ve included digital cameras as a keyword, your ad headline could be “Buy Digital Cameras.”

Read more here: https://support.google.com/google-ads/answer/1704392