Which of the following idioms represents the meaning 'Laugh uncontrollably'?

Fall about: English Meaning: laugh uncontrollably / to laugh without being able to stop.Bangla Meaning: হাসিতে ভেঙ্গে পড়া।Ex. Sentence: We fell about when we heard her reply.Bangla Meaning: তার উত্তর শুনে আমরা হাসিতে ভেঙ্গে পড়লাম।Other options,Fall flat - fail completely to produce the intended or expected effect.Fall off - 1. decrease in number, amount, intensity, or quality.2. become detached and drop to the ground.Fall on hard times - to lose your money and start to have a difficult life.Source: Website lecture.