in c++. Write a function that returns the sum of all the elements in a specified column in a matrix using the following header: const int SIZE = 4; double sumColumn(double m[][SIZE], int rowSize, int...

in c++.

Write a function that returns the sum of all the elements in a specified column in a matrix using the following header: const int SIZE = 4; double sumColumn(double m[][SIZE], int rowSize, int columnIndex);

Write a test program that reads a 3-by-4 matrix and displays the sum of each column.