Explanation:

- The sentence is: One day, the queen was painting when a messenger entered ____________ to convey the king's arrival.

- Option 1: comparably — This means in a similar way, which doesn't fit the context.

- Option 2: relatively — This means in relation to something else, not suitable here.

- Option 3: enjoyably — Entering in an enjoyable way doesn't make sense for a messenger.

- Option 4: breathlessly — This means out of breath, usually from hurry or excitement, which matches the urgency of a messenger delivering important news.

The correct answer is:

Option 4: breathlessly