a. Row Matrix : Matrix of order `1 xx m` is called row matrix `[ 12" "13" "45 ]` is an example of order `1 xx 5`
b. Column Matrix : Matrix having exactly one column is called a column matrix order : `n xx 1`
`[[a], [b], [c]]` is an example of column matrix.
c. Horizontal Matrix : If number of rows is less than no. of columns, then it is called horizontal matrix. If matrix `A` has order `m xx n`, then `m lt n` eg : `[[1, 2, 3, 5], [-3, 2, 7, 5]]` is horizontal matrix.
d. Vertical Matrix : If `m gt n`, then it is called vertical matrix.
ex : - `[[1, 2], [1, 2], [2, 3]]`
e. Zero or Null matrix : If all the elements of a matrix are zero then it is called null matrix. A null matrix is denoted by `0`.
`0 to` Number `0`
`0 to` Null matrix

Options

A. idempotent matrix
B. involutory matrix
C. nilpotent matrix
D. None of these

Answer

C