There are 4 gear wheels on fixed axles next to each other, as shown. The first one has 30 gears, the second one 15, the third one 60 and the last one 10. How many revolutions does the last gearwheel make when the first one turns through one revolution?

(A) 3 (B) 4 (C) 6 (D) 8 (E) 9