Which sentence below shows correct use of em dashes? A. In a-thousand-years, most of our greatest monuments such as they are will have crumbled to nothing.

B. In a thousand years, most of our greatest monuments – such as they are – will have crumbled to nothing.

C. In a thousand years, most of our greatest – monuments such as – they are will have crumbled to nothing.

D. In a thousand years, most of our greatest monuments such as they are will have crumbled-to-nothing.