Consider a sequence of 2-dimensional vectors: $\mathbf{v}_1 = [10, 11]$, $\mathbf{v}_2 = [20, 21]$, $\mathbf{v}_3 = [30, 31]$, $\mathbf{v}_4 = [40, 41]$, and $\mathbf{v}_5 = [50, 51]$. A matrix $\mathbf{V}_{[j,k]}$ is formed by stacking the vectors from index $j$ to $k$ as rows. If the current position is $i=4$ and the context window size is $n_c=3$, which of the following matrices correctly represents $\mathbf{V}_{[i-n_c+1,i]}$?

Dimensions of a Context Window Matrix

You are given a sequence of 2-dimensional vectors: $\mathbf{v}_1 = [1, 2]$, $\mathbf{v}_2 = [3, 4]$, $\mathbf{v}_3 = [5, 6]$, $\mathbf{v}_4 = [7, 8]$, $\mathbf{v}_5 = [9, 10]$, and $\mathbf{v}_6 = [11, 12]$. A matrix is constructed using the notation $\mathbf{V}_{[i-n_c+1,i]}$, where $i$ is the current position and $n_c$ is the context window size. If the resulting matrix is $\begin{pmatrix} 5 & 6 \\ 7 & 8 \\ 9 & 10 \end{pmatrix}$, what were the values of $i$ and $n_c$ used to create it?