The figure shows a person estimating the height of a tree by looking at the top of the tree with a mirror. Assuming that both the person and the tree form right angles with the ground, which of the following proportions can be used to estimate the height of the tree?


A. 7/h = 6/3
B. 6/h = 3/7
C. 3/h = 7/6
D. 6/h = 7/3