A. You can remember which axis is which by Y-axis is the vertical one (Y to the sky) and X- axis is horizontal. it's not C because you don't have a second point. It's not (0,4) it's just 4.
For Answer A, it is 3/4 because there are 4 donuts in total and you have 3 glazed and 1 chocolate, so it will be 3 over 4.
For Answer B, it is 75% because 3 over 4 is 0.75 and if you put it in percentage, then it will be 75%.
As x approaches 3 from the right, the limit is 3. There is a closed hole up there AT x=3 y=7, but we don't care about what happens AT x=3, only what happens as x APPROACHES 3.
Not sure if this is what your looking for but 25x10=250