An engineer is building a model to classify customer reviews as 'positive' or 'negative'. The input text is first prepared by adding a special classification token to the very beginning. This entire sequence is then processed by an encoder, which generates a final output vector for each token. To make the final classification decision for the entire review, which specific vector should be passed to the final classification layer?

A data scientist is using a pre-trained Transformer model for a sentiment analysis task (classifying text as positive or negative). Arrange the following steps in the correct order to form the classification pipeline.

Diagnosing a Flawed Classification Pipeline