Fall out: ‘have an argument, to argue with someone and stop being friendly with them’:
After a long standoff, Emily had fallen out with her family.
Sales of these products have fallen off in recent months.
Fall off: ‘to become detached and drop to the ground, to drop unintentionally to the ground from (a high object, bicycle, etc), especially after losing one’s balance’:
The plaster of his bedroom has now come away from the wall and fallen off.
The handle of my suitcase just fell off suddenly.
Fall apart: ‘break up, come apart, or disintegrate’:
Their marriage was likely to fall apart when she discovered his husband had been seeing another woman.
These shoes weren’t the best quality and fell apart very easily.
To break owing to long use or poor construction:
Don’t push the door forcefully, the latch may come apart.
The chassis of the old car is falling apart.
To become disorganized and ineffective:
Since you have no intention to continue, this project will finally fall apart.
Go to pieces:
The dryer finally broke. The old bed finally fell apart completely.
Fall away: ‘fall away(in sport) play less well’:
When he got out, the whole team fell away.
By early in the second half the whole team was exhausted and fell away.
Ans: (B) Out.