An industrial machine uses a compound gear train to drive a heavy load, as shown in the diagram below.

Gear A (16 teeth) meshes with Gear B (48 teeth). Gear B is fixed coaxially to Gear C (12 teeth) on a common shaft, meaning they rotate together. Gear C meshes with Gear D (40 teeth).
If the input Gear A is rotated 150 times, how many times does the output Gear D turn?
15 times
60 times
150 times
1500 times