What is the best way to: How to make a simple window seat in a bedroom?

Choices:
[A]. Collect and paint some cinder blocks, stack them closely together and then drill a wood panel into the cinder and set it at the top of the window outside a room.
[B]. Collect and paint some cinder blocks, stack them closely together and then drill a wood panel into the cinder and set it at the base of the window inside a room.
Answer:
[B].