The answer is A.
The way you know this is by graphing the first function.
The second function is in a different format, so you just have to isolate Y.
-1/3x + y = -1
y= 1/3x -1 OR y= -1 + 1/3x
both of the functions have the same slope, but different y-intercepts. therefore, they'll never touch. making them infinite solutions.
it's also A because both of the slopes are positive, the slopes in graph D are negative.
So, the answer is A.
Hope this helps! xx