Advanced Grammar Challenge Mode: Subject-Verb Agreement Edition

Warning: this is not for the faint of heart. You will be tested on the most arcane, the most obscure, and the most utterly confusing aspects of subject-verb agreement. Your sanity may be questioned, but your knowledge of grammar rules will be... well, somewhat intact.

Here's your mission:

• Identify the correct subject-verb agreement in the following sentences:
• 1. The cat in the hat is eating a mouse in the house.
• 2. The many cats in the city are sleeping in the park.
• 3. The one cat in the city is sleeping in the park.

Your progress will be monitored by The Grammar Gauntlet, and if you fail, you will be subjected to the consequences.