Just wanted to let you all know of a new feature for your posting--Spoilers!
When posting a question where you wish to hide the OA, try wrapping a
around your answer. Here's an example (hover over the black area):
OA: The answer is B
You will see the new spoiler button to the top right of your posting menu:
I haven't 100% tested this new feature yet, so let me know if you encounter any problems with posting. Thanks!