A system of linear equations is said to be consistent independent if the lines intersect each other only once, then there is only one solution, a system is said to be consistent dependent if the equations represent the same line and then they intersect each other in every point over the line and there are an infinite number of solutions. A system is said to be inconsistent if the lines are parlallel ad then they never intersect and there is no solution for the system.
According to the above definition, system A is consistent independent because the lines intersect only once and this means it has a unique solution.
System B is consistent dependent because both equations represent the same line and this means it has an infinite many solution.
System C is inconsistent because the lines never intersent each other and then this means system has no solution.