Which of the following copy is most likely to be compliant with Amazon's creative acceptance policies?

Upgrade today" is the most compliant option because it is a neutral call to action (CTA) that encourages a user action without creating undue urgency or making unsubstantiated claims. Amazon's creative acceptance policies generally disallow language that creates a false sense of urgency, makes superlative claims without proof, or uses excessive capitalization. "UNMISSABLE SUMMER DEALS!" uses excessive capitalization and a superlative ("UNMISSABLE") which is likely to be non-compliant as it makes a strong, unproven claim. "Shop now!" is a common CTA but is less specific than "Upgrade today" and can sometimes be flagged if used in a context that implies immediate, time-sensitive action without justification. "Hurry while supplies last" directly creates a sense of urgency, which Amazon policies often restrict unless there's a verifiable, limited-time offer or stock constraint, making it generally non-compliant for standard ad copy.