How hard the noise made it for us______ A fell asleep B fall asleep C to fall asleep D falling asleep

How hard the noise made it for us______ A fell asleep B fall asleep C to fall asleep D falling asleep
How hard the noise made it for us______
A fell asleep B fall asleep C to fall asleep D falling asleep

How hard the noise made it for us______ A fell asleep B fall asleep C to fall asleep D falling asleep
C
it是形式宾语
这句话可以转化成The noise made it hard for us to fall asleep.

C to fall asleep