So first of all you count all the blocks, so it will be 16 blocks (4x4) sideways and horizontal.
A = 16/4 marked blocks = 25%
B = 16/8 marked blocks = 50%
C = 16/6 marked blocks = ?
D = 16/10 marked blocks = 62,5%
<em>So answer would be A </em>
I believe the answer is 420
If my calculations are correct, Colton swam 288 yards. Really hope this helps.