entries of incidence matrix of undireccted graph What is the sum of the entries in a row (respectively column) of the incidence matrix for an undirected graph?

I didn't fully understand the question, does it require a number as an answer or just an explanation? I tried to solve it, but all I got is that the rows are the vertices and the columns are the edges and I couldn't proceed
The sum on each column of the matrix is 2 because each edge is connecting two vertices.
The sum on each column of the matrix is 2 because each edge is connecting two vertices.