AMC 12 2007a Problem 2

An aquarium has a rectangular base that measures 100 cm by 40 cm and has a height of 50 cm. It is filled with water to a height of 40 cm. A brick with a rectangular base that measures 40 cm by 20 cm and a height of 10 cm is placed in the aquarium. By how many centimeters does the water rise?

$\mathrm{(A)}\ 0.5 \mathrm{(B)}\ 1 \mathrm{(C)}\ 1.5 \mathrm{(D)}\ 2 \mathrm{(E)}\ 2.5$