• 30
• 40
• 10
• 20

The correct answer is: 20

Explanation: In a Google App campaign, the maximum number of HTML, image, and video assets per ad group is 20. Specifically, for image assets, a financial company can add up to 20 images within a single ad group. These image assets are used in ads to represent the app on a vast network of over three million sites and apps. Each ad group allows for a maximum of 20 images, providing ample opportunity to create diverse and engaging visual content to promote the app effectively.