To predict the total cost for buying 10 of the type A markers, we can look at the solid line labeled A on the graph. This line passes through the points (0,0) and (3,6).
From the graph, we can see that for every 1 marker, the total cost increases by $2. Therefore, for 10 markers, the total cost would increase by $2 x 10 = $20.
So, the correct answer is:
$20.00