A plane mirror is placed on the level bottom of a swimming pool that holds water (n = 1.33) to a depth of 2.5 m. A small toy is suspended 1.9 m above the mirror. An observer above the water looks vertically downward at the toy and its image in the mirror. The apparent difference in depth between the toy and its image in the mirror is closest to:
a) 1.6 m
b) 2.5 m
c) 2.9 m
d) 1.9 m
e) 2.2 m