The value of a determinant is unaltered if :

two rows are interchanged two columns are interchanged every element is a row (or column) is multiplied by the same number to each element of a row (or a column) is added equi-multiplies of the corresponding elements of another row ( or column)

to each element of a row (or a column) is added equi-multiplies of the corresponding elements of another row ( or column)

The correct answer is option (4) : to each element of a row (or a column) is added equi-multiplies of the corresponding elements of another row ( or column)