Question:
An archer fires an arrow from the ground so that it passes through two hoops, which are both a height h above the ground. The arrow passes through the first hoop one second after the arrow is launched, and through the second hoop another second later. What is the value of h?
(A) 5m.
(B) 10m.
(C) 12m.
(D) 15m.
(E) There is not enough information to decide.