You are miguel Cervantes de Navas y colon, captain in the royal spanish army in Sevilla in the year 1842. Outside your barracks window is a stack of cannonballs, as shown in the illusion. On an idle afternoon you dicide to calculate the number of cannonballs in the stack. What is the number of cannonballs? A. 650 B. 506 C. 623 D. 571