A sequence model processes the sentence 'The quick brown fox jumps over' and generates a hidden state vector for each word. The vectors are indexed starting from 1, so the vector for 'The' is represented as (\mathbf{h}_1), for 'quick' as (\mathbf{h}_2), and so on. Which of the following correctly represents the sequence of hidden state vectors for the specific phrase 'brown fox jumps'?

Representing a Subsequence of Hidden States

A sequence of hidden state vectors is represented as $\mathbf{h}_7, \mathbf{h}_8, \dots, \mathbf{h}_{15}$. This sequence contains a total of ____ vectors.