1. The problem asks for the dimensions of the matrix or vector given as $[4 \quad -1 \quad 2]$. 2. Dimensions of a matrix or vector are given as $\text{rows} \times \text{columns}$. 3. The given matrix has 1 row and 3 columns because the numbers are arranged horizontally in a single row. 4. Therefore, the dimensions are $1 \times 3$. 5. Comparing with the options: - A. $3 \times 1$ means 3 rows and 1 column (vertical vector). - B. $2 \times 3$ means 2 rows and 3 columns. - C. $1 \times 3$ means 1 row and 3 columns (matches our matrix). - D. $1 \times 1$ means a single element. 6. The correct answer is C. $1 \times 3$.