Subject-Verb Agreement Correction

During a recent history project, Sarah and her team were tasked with presenting the causes of the American Revolution. They worked diligently on their presentation, ensuring that each member contributed their unique perspective. However, as they were finalizing their slides, they noticed several errors in grammar and punctuation. One particular sentence in the presentation read: 'The Boston Tea Party were a pivotal event that stirred the colonies towards independence.' Which of the following corrections should be made to improve the grammatical accuracy of this sentence?