Final answer:
The first column of a matrix is referred to as a vector, which is a one-dimensional array of numbers within the matrix.
Step-by-step explanation:
The first column of a matrix is known as a vector. A vector is a one-dimensional array of numbers. In the context of matrices, option d) Vector is correct for describing the first column of a matrix. A row refers to a horizontal arrangement of elements, an element is an individual value within the matrix, and the determinant is a special number that can be calculated from a square matrix.