Given a 4x5 matrix, what could a row of 0's represent geometrically?

My attempt:

Given a scalar PLANE equation, you could make a 3x3 matrix and solve the system of equations.

A row of zeroes there could represent a consisten but dependent solution,

The planes would intersect in a line.

But PLANES only have 3 variables.

we were given FOUR equations and FIVE variables and we had to make a matrix out of that.

I'm not sure what shape that would make because first of all, whatever that equation represents, is in 4-space. It COULD be a moving plane, right?

But what would four of those make if they intersect at a line?