The lower window of a house is at a height of 2 m above the ground, and its upper window is 4 m vertically above the lower window. At a certain instant, the angles of elevation of a balloon from:
A) Both the windows are the same
B) The lower window is greater than that from the upper window
C) The upper window is greater than that from the lower window
D) The upper window is double that from the lower window