For the first time around your loop you plot:
plot(data(1, 1:2), data(1, 3:4));
that corresponds to using [1000 1000] from A as X-coordinates, and [1003 2640] as Y-coordinates of your line.
I don't think that's what you want. Have a think about what lines you want to plot (manually, perhaps for only 2-3 rows
of A and B) and how you need to loop over the rows to achieve that. Homework hint: you are allowed to use nested loops.