Analyze the following customer feedback for a new laptop: 'The display is vibrant and the keyboard is comfortable, but the battery life is shockingly poor.' Which word in this feedback is the strongest indicator that the overall opinion is negative?

Crafting a Negative Sentiment Snippet

A team is building a system to automatically identify customer complaints. They need to train the system with the most unambiguous examples first. Which of the following customer reviews provides the clearest and most direct example of a negative opinion?