Answer
a.
Work Step by Step
Start by considering $[-40,40,20]$ along the $x$-axis. From this, we can conclude that the distance between two ticks along the $x$-axis is $20$, and the maximum $x$ value is $40$. Also, with $[-1000,1000,100]$, we know that the maximum $y$ value is $1000$ and the distance is $100$. By counting the ticks visible in the graph along the $x$-axis and $y$-axis, we can eliminate all the other choices and choose a.